Soles for sports shoes

ABSTRACT

Improved soles and insoles for shoes, in particular sports shoes, are described. In an aspect, a sole for a shoe, in particular a sports shoe, with at least a first and a second surface region is provided. The first surface region comprises expanded thermoplastic polyurethane (“TPU”). The second surface region is free from expanded TPU.

CROSS REFERENCE TO RELATED APPLICATION

This application is related to and claims priority benefits from GermanPatent Application No. DE 10 2012 206094.4, filed on Apr. 13, 2012,entitled SOLES FOR SPORTS SHOES (“the '094 application”), and EuropeanPatent Application No. 13151596.7, filed on Jan. 17, 2013, entitledSOLES FOR SPORTS SHOES (“the '596 application”). The '094 and '596applications are hereby incorporated herein in their entireties by thisreference.

FIELD OF THE INVENTION

The present invention relates to soles for shoes, in particular solesfor sports shoes, comprising expanded thermoplastic polyurethane.

BACKGROUND

By means of soles, shoes are provided with a variety of differentproperties that may, depending on the specific type of shoe, be realizedto different extents. Primarily, shoe soles usually serve protectivepurposes. By means of their stiffness, which is increased when comparedto the stiffness of the shoe upper, shoe soles protect the respectivewearer's foot from injuries caused for example by sharp objects that thewearer of the shoe steps upon. Moreover, a shoe sole usually protectsthe shoe from excessive abrasion by means of its increasedabrasion-resistance. Further, shoe soles may increase the grip of a shoeon the respective ground and may thus facilitate quick movements. It maybe a further function of a shoe sole to provide a certain stability. Inaddition, a shoe sole may provide a cushioning, for example to damp theforces that occur when the shoe contacts the ground. Finally, a shoesole may protect the foot from dirt or splash water or it may provide amultitude of further functionalities.

In order to meet this plethora of functionalities, various materials areknown in the prior art out of which shoe soles may be manufactured. Forexample, shoe soles may be manufactured from ethylene-vinyl acetate(“EVA”), thermoplastic polyurethane (“TPU”), rubber, polypropylene(“PP”) or polystyrene (“PS”). Each of these different materials providesa specific combination of different properties that are more or lesswell suited for soles of specific types of shoes, depending on theparticular requirements of the respective type of shoe. For example, TPUis very abrasion-resistive and tear-resistant. Moreover, EVA provides ahigh stability and relatively good cushioning properties.

It is a common disadvantage of the aforementioned materials that shoesoles made from of these materials have to be manufactured separatelyand subsequently have to be attached to the shoe upper, e.g. by gluingor sewing. From WO 2008/087078, WO 2007/082838, WO 2010/136398, and WO2005/066250, expanded TPU is known, which may be used for manufacturingshoe soles. For example, WO 2005/066250 describes that a shoe soleformed out of expanded TPU may be attached to a shoe upper withoutadditional gluing means. Further, WO 2005/066250 discloses that theexpanded TPU is foamed in a tool in contact with the shoe upper and,thus, a sole made of expanded TPU is provided that adheres to the shoeupper. In addition, WO 2005/066250 describes the possibility ofpre-manufacturing an outsole of thermoplastic elastomer (e.g. polyvinylchloride (“PVC”), thermoplastic rubber, TPU) and, after its curing,providing expandable TPU in the form of foam to a cavity between theoutsole and the shoe upper. Hence, the outsole does not need to be gluedto the shoe upper.

However, the disclosure of WO 2005/066250 describes the disadvantagethat the properties of the sole are influenced by the sole of expandedTPU continuously over the entire surface. A fine control of the soleproperties is not possible according to WO 2005/066250.

It is therefore desirable to provide improved soles for shoes, inparticular sports shoes. It is further desired to provide improvedpossibilities to construct such soles from expanded TPU.

SUMMARY

The terms “invention,” “the invention,” “this invention” and “thepresent invention” used in this patent are intended to refer broadly toall of the subject matter of this patent and the patent claims below.Statements containing these terms should be understood not to limit thesubject matter described herein or to limit the meaning or scope of thepatent claims below. Embodiments of the invention covered by this patentare defined by the claims below, not this summary. This summary is ahigh-level overview of various aspects of the invention and introducessome of the concepts that are further described in the DetailedDescription section below. This summary is not intended to identify keyor essential features of the claimed subject matter, nor is it intendedto be used in isolation to determine the scope of the claimed subjectmatter. The subject matter should be understood by reference toappropriate portions of the entire specification of this patent, any orall drawings and each claim.

According to certain embodiments, a sole for a shoe, in particular asports shoe, comprises at least a first and a second surface region,wherein the first surface region comprises an expanded TPU, inparticular randomly arranged particles comprising expanded TPU, andwherein the second surface region is free from expanded TPU.

A combination of a surface region of expanded TPU and a surface regionthat is free from expanded TPU, e.g. made from different materials,provides the properties of expanded TPU specifically in those locationswhere these properties are desired and combines these properties withdifferent properties in a different surface region.

Expanded TPU distinguishes itself by means of its good elastic andcushioning properties. For example, expanded TPU may be particularlycushioning. Thus, external shocks that arise for example when the solehits the ground may thus be dampened well such that a pleasant wearingcomfort is achieved. In addition, expanded TPU can provide largeelasticity. By means of a large elasticity, the energy that is absorbedfor deforming the sole is released again by the sole. Thus, the energyis not lost. This energy may be used by for example a runner after thesole has hit the ground since the sole springs back essentially withoutany loss of energy.

Expanded TPU also provides a large long-term stability, i.e. even whenexposed to permanent external forces it only deforms to a small extent.Therefore, this material is particularly well suited as material forshoe soles. Moreover, it turns out that the mechanical properties ofexpanded TPU are essentially temperature-independent over a wide rangeof temperatures. Thus, by means of this material, the properties of ashoe sole may be simultaneously optimized over a wide range oftemperatures. Therefore, sports shoes, e.g. jogging shoes, with a solethat comprises a first surface region of expanded TPU may be used bothfor winter and summer temperatures, e.g. in a range from about 0° C.-30°C. without any substantial change to its functionality, e.g. a changedcushioning. In contrast, the material EVA, which is widely used for shoesoles in the prior art, comprises a significantly largertemperature-dependence.

A further advantage of expanded TPU is that it has been found to provideup to about 30% better heat insulation as compared to conventionalmaterials used for sole design known from the prior art. It maytherefore be used in winter sports apparel, in particular winter shoes,where good heat insulting properties may be desirable.

By means of a first surface region that comprises expanded TPU, forexample in the heel region of a sole, a particularly large cushioningmay be achieved, whereas by means of using a stiffer material in theremaining region of the sole, an increased stability may be achieved.The advantageous material properties of the expanded TPU may in total beexactly adapted to the needs of the respective sole and, thus, a solemay be designed in an optimized manner both area-wide and modularly.

Using expanded TPU for a sole that comprises at least two surfaceregions is also advantageous because this material may be attached to avariety of other materials without the need for additional gluing means.It enables a combination with second surface regions made from a varietyof expandable and not expandable materials, such as EVA, TPU, rubber,PP, expanded PP, PS, polyamide, polyether block amide (“PEBA”),polyoxymethylene (“POM”), polyethylene (“PE”), polyoxyethane (“POE”),ethylene propylene diene monomer (“EPDM”), etc. Hence, the designpossibilities for the first and second surface regions are almostunlimited. The present invention opens up a variety of designpossibilities for novel shoe soles.

A partial region of a sole, as being used herein, is an arbitrary shapedpart of a sole. In contrast, a surface region specifies a specificpartial region of a sole, namely a partial region that continuouslyextends from the lower surface of the sole to the upper surface of thesole. The term partial region of a sole comprises surface regions of thesole but also for example a sole layer or a surface region of a solelayer or other partial regions of the sole.

In certain embodiments, the surface regions of the sole are bonded toeach other by a steaming process for the expanded TPU. Surprisingly,this may be carried out with a variety of materials that may be used forthe second surface region, for example those specified above. Theresulting bond is strong enough to resist the large forces thattypically act on a shoe sole. Hence, the surface regions do not have tobe additionally glued or sewed. However, in other embodiments, thesurface regions may be further bonded together by a foil, such as a foilcomprising TPU. Bonding the surface regions by means of the steamingprocess allows a less labor-intensive, faster, and, thus, also cheaperproduction. Moreover, the precision of the connection is significantlylarger in a steaming process, as compared to for example sewing orgluing, and it may be automated more easily. In addition, a moreenvironmentally-friendly manufacturing method with increasedlabor-safety is provided by avoiding gluing means since gluing meansusually are hazardous to health and/or harmful to the environment.

In further embodiments, the second surface region comprises a foamedEVA. The combination with foamed EVA allows a second surface region thatcomprises good cushioning and that provides increased stability to thesole.

In some embodiments, the second surface region comprises a non-expandedTPU. A combination with non-expanded TPU is also advantageous since theexpanded and the non-expanded TPU bond to each other particularly well.As a result, a particularly durable sole may be provided. Further, byusing non-expanded TPU, the second surface region may be provided with alarge tear-resistance and abrasion-resistance. In some embodiments, thenon-expanded TPU serves as outsole material.

In further embodiments, the second surface region comprises rubber. Bymeans of using rubber, the second surface region may e.g. be providedwith a large slip-resistance.

In further embodiments, the second surface region comprises PP. PPallows a high hardness and simultaneously a relatively low weight of thesecond surface region.

In further embodiments, the second surface region comprises a polyamide(“PA”). By means of PA, a particularly stiff second surface region maybe provided.

In further embodiments, the second surface region comprises PS. By meansof using PS, second surface regions may be provided that areparticularly hard and simultaneously comprise low weight.

In further embodiments, the second surface region comprises one or moreof PEBA, POM, PE, POE and/or EPDM.

In some embodiments, the second surface region comprises expanded PP.Expanded PP is an extremely light yet stable material. It can thereforebe used in combination with expanded TPU to provide a light-weight solethat provides good stability, cushioning and energy return. In certainembodiments, the complete sole has a weight of less than about 100 gand, in other embodiments, the complete shoe has a weight of less thanabout 100 g. In certain embodiments, the ratio of expanded PP andexpanded TPU may be about 70% expanded PP to about 30% expanded TPU. Inother embodiments, the expanded TPU may comprise about 10%-30% of theentire sole, and may further comprise about 15% of the entire sole.

In yet other embodiments, the second surface region may comprise one ormore different materials, for example EVA or any other materialdiscussed herein, in addition to or in place of the expanded PP. Incertain embodiments, the expanded TPU may comprise about 10%-40% of theentire sole, may further comprise about 10%-30% of the entire sole, andmay even further comprise about 15% of the entire sole, depending on thespecific sole design and intended use of the sole. In yet otherembodiments, the first surface region comprising expanded TPU maycomprise less than about 40% of the entire sole, may further compriseabout 10%-30% of the entire sole, and may even further comprise about15% of the entire sole.

In some embodiments, the second surface region is arranged at a rim ofthe sole. Thus, for example the stability and/or the slip-resistance ofthe sole may be increased at the rim of the sole by means of the secondsurface region. Moreover, a twisting of the foot may thus becounteracted. Arranging the second surface region at a rim of the sole,in this context, allows for minimizing of the second surface region.

In further embodiments, the second surface region comprises a sole plateand/or a torsion bar and/or an outsole and/or a recess for receivingfunctional elements. Functional elements may for example be frames thatare specifically adapted for sprinting shoes and/or a unit forsupporting the cushioning of shear forces and/or an element forsupporting the pronation and/or an electronic unit.

By means of using the specified elements in the second surface region,the functionality of the sole may be further improved. In certainembodiments, the elements are pre-fabricated. The elements are bonded ina precise manner to a first surface region by means of a steamingprocess for the first surface region.

In some embodiments, the first surface region comprises a varyingthickness. By means of the varying thickness, the properties of thesurface region may be precisely controlled. By means of a largerthickness at specific locations, e.g. an increased cushioning may beprovided. Moreover, by means of varying the thickness, a specificprofile of the sole may be achieved. By means of using expanded TPU,surface regions with varying thickness may be manufactured in anadvantageous manner. By means of the longevity of the expanded TPU, thevariation of the thickness will be permanently maintained even if thesole is heavily used.

The thickness of the first surface region may increase from the forefootregion of the sole towards the heel region. Thus, an increased stiffnessmay be achieved in the heel region. Moreover, that way, the weight ofthe sole may be increased towards the heel region in order to provide amore natural wearing feeling.

In some embodiments, the first surface region comprises at least onerecess. Hence, the first surface region, in fact, only has to beprovided to the extent to which it is actually needed. Weight and costsof the sole are thus reduced.

In further embodiments, the first surface region is essentially arrangedat a rim of the sole. By means of arranging it at a rim of a sole, insome embodiments, essentially the entire stepping surface of the solemay be supported by means of the first surface region. To this end, thefirst surface region does not necessarily have to be arranged in theinternal region of the sole. Thus, the surface of the first surfaceregion may be minimized substantially without any loss of functionality.

The thickness of the first surface region may be increased at the rim ofthe sole. As large forces arise, for example by means of changing thedirection of running, such as at the rim of the sole, an increasedthickness may provide a correspondingly increased stiffness in thatlocation.

In certain embodiments, the first surface region is arranged in themidfoot region and/or in the forefoot region of the sole. Hence, aparticularly large cushioning may be provided in the midfoot regionand/or the forefoot region of the sole. An increased cushioning isparticularly desirable in these regions and/or in one of these regionsfor many types of shoes, for example for basketball shoes, since oftenthe primary contact between sole and ground occurs in these regionsand/or in one of these regions during fast movements.

In further embodiments, the sole comprises a third surface region thatcomprises an expanded TPU. By means of the advantageous manufacturing ofexpanded TPU, it is also possible to include a third surface region ofthis material into the sole. Thus, further design possibilitiesconcerning the functionality and the appearance of the sole areprovided.

In certain embodiments, the first surface region is located in the heelregion of the sole, wherein the third surface region is arranged in themidfoot region and/or in the forefoot region of the sole. Thus, both inthe midfoot region and/or the forefoot region and in the heel region ofthe sole, an increased cushioning may be provided without having to usethe expanded TPU continuously therebetween. Rather, an intermediateregion may remain free such that material, weight, and costs may besaved.

In other embodiments, it may also be desirable to have the complete heel(i.e. the full thickness and the full width of the heel) and/or thecomplete midfoot region comprising expanded TPU, e.g. if a particularlycushioning sole is desirable.

In other embodiments, the first surface region is arranged in themidfoot region and/or the forefoot region and the sole further comprisesa partial region arranged in the heel region of the sole.

In certain embodiments, the partial region comprises a heel insertcomprising an elastomer compound, for example a highly viscose EVA basedcompound. One example for such a highly viscose EVA based compound isdescribed in document DE 100 10 182.9-09.

A combination of a first surface region comprising expanded TPU and sucha heel insert is of particular advantage for use in a heat insulatingfootwear, for example a winter shoe or a hiking shoe. The expanded TPUprovides a high rate of energy return, while having extreme temperaturestability in high/low temperature regions and high heat insulatingproperties. This is of particular importance for winter footwear, wherethe expanded TPU can insulate the wearer's foot against the cold andincrease the overall comfort while still providing a good feel of theground. The heel insert, in particular a heel insert comprising anelastomer compound can absorb the energy that is applied to the solewith the first impact of the foot on the ground. The absorption of thisshock energy is important to prevent injuries and a heel insertcomprising an elastomer compound, such as for example a highly viscoseEVA based compound, is particularly well suited for this purpose.Another advantageous effect of a heel insert as described above is toprovide better stability on uneven surfaces.

In certain embodiments, the first surface region and/or the thirdsurface region and/or the partial region are surrounded by the secondsurface region. Thus, for example the stability of the first surfaceregion and/or the third surface region and/or the partial region may beincreased. Moreover, the functionality of the first surface regionand/or the third surface region and/or the partial region may thus beinfluenced since for example the possible extension of the first surfaceregion and/or the third surface region and/or the partial region may belimited by the second surface region.

In further embodiments, the sole comprises a reinforcement material, forexample to improve the stability of the sole. The reinforcement materialmay be a fiber-like reinforcement material or a textile reinforcementmaterial. The textile reinforcement material may be woven or non-woven,layered, or knitted. The reinforcement material can further benon-stretchable; it may be tear resistant and may comprise strong fibersand/or a strong textile material. In some embodiments, the reinforcementmaterial is attached to at least a part of one of the surface regionsand/or a part of the partial region. In other embodiments, thereinforcement material is glued to at least a part of the surfaceregions and/or a part of the partial region. In yet other embodiments,the reinforcement material is attached to at least a part of the surfaceregions and/or a part of the partial region by the use of a foil, inparticular a foil comprising TPU, as further described below.

The use of a reinforcement material, in particular a textilereinforcement material, facilitates the construction of an extremelylight-weight sole. For example, instead of a frame, the textilereinforcement material may be used to provide the necessary stability tothe sole in combination with a second surface region comprising alight-weight material, such as expanded polypropylene.

In further embodiments, one or more surface regions and/or the partialregion are at least partially surrounded by a foil, in particular aplastic foil. The foil may comprise a TPU, PA, polycarbonate and/orcarbon fiber and/or other material. By means of using foils, on the onehand, the external appearance of the one or more surface regions and/orthe partial region may be modified. The foil provides the surfaceregions and/or the partial region e.g. with a specific color and/or aspecific texture. Moreover, the foil may also modify a functionality ofthe one or more surface regions and/or the partial region. For example,the foil may be designed such that its geometry limits the extension andthus the cushioning properties of e.g. the first surface region. On theother hand, the foil may influence the surface properties of the one ormore surface regions and/or the partial region, for example theirhydrophobicity or their stiction. In addition, the foil may serve asdecoration, as outsole, as sole plate, and/or as connecting element. Thefoil may have a thickness of about 0.05 mm to about 1 mm. In some cases,the foil may have a thickness of several millimeters.

In certain embodiments, the foil is bonded to at least a part of the oneor more surface regions and/or a part of the partial region by partiallymelting at least a part of the foil and/or a part of the one or moresurface regions and/or a part of the partial region. In someembodiments, the foil is bonded to at least a part of the surfaceregions and/or a part of the partial region by a chemical reaction.

By bonding the foil and the surface regions and/or the partial regionthrough a chemical reaction, the bond is of particular durability andcannot be separated through mechanical influence, e.g. during running.

In further embodiments, the foil is imprinted on the side of the foilfacing the one or more surface regions and/or the partial region. Byimprinting the foil on this side, the printing is protected againstmechanical or chemical influences while wearing the shoe and increasesdurability of the printing. Additionally, or alternatively, the foil mayalso be imprinted on the side facing away from the one or more surfaceregions and/or the partial region.

In yet other embodiments, the foil is used to attach one or more furtherinner sole elements to one or more surface regions and/or the partialregion. An inner sole element is a functional element that is disposedbetween at least one surface element and/or the partial element and thefoil. By disposing the functional element between the at least onesurface element and/or the partial element on the one side and the foilon the other side, the functional element is further secured in itsposition and protected against mechanical or chemical influences. Thisis of particular importance for easily damageable functional elements,e.g. electrical elements.

In further embodiments, the foil can act as a means to attach furtherouter sole elements to the midsole. Outer sole elements are functionalelements that are bonded to the midsole by use of the foil and aredisposed on top of the foil.

In further embodiments, the foil may be used in combination with bothinner and outer sole elements as described above.

In some embodiments, an inner sole element and/or an outer sole elementcomprises one of a sole plate, an outsole element, a torsion bar, and atextile reinforcement material.

In other embodiments, the foil and the inner and/or outer sole elementscomprise a similar material, in particular TPU, such that they may bebonded together very well by a chemical bond without the use ofadditional adhesives. This provides for the advantageous effects alreadydiscussed above.

Further embodiments comprise coloring part of the sole comprising TPU,in particular one or more surface regions comprising TPU and/or a foilcomprising TPU, with a color comprising TPU. By using a color comprisingTPU to color these parts, the coloring is extremely durable andinseparably bonded to the respective parts of the sole through achemical reaction.

In certain embodiments, a sole for a shoe, in particular a sports shoeis provided comprising a partial region, wherein the partial regioncomprises an expanded TPU. The sole in addition comprises a surfaceregion that is free from expanded TPU. Also this aspect may be combinedwith embodiments that are described herein.

In further embodiments, a problem of the present invention is solved bymeans of a sole for a shoe, in particular a sports shoe, comprising afirst partial region that comprises a first expanded TPU and a secondpartial region that comprises a second expanded TPU, wherein the firstexpanded TPU and the second expanded TPU are manufactured using adifferent steaming process and/or using a different base material.

Such a sole comprises the advantageous properties of expanded TPU thatmay, in addition, be locally adapted to the specific requirements at afirst and a second partial region. The advantageous properties of theexpanded TPU, such as for example large cushioning andtemperature-independence, may thus be used and at the same time aflexible design of the sole with different properties in at least afirst and a second partial region may be provided.

Using a different steaming process for the first and the second expandedTPU allows manufacturing two partial regions with different propertiesout of a single base material. Therein, by means of gradual changes inthe steaming process (for example of the pressure, the density or thetemperature), the properties of the corresponding expanded TPU may befine controlled. Hence, different properties may be achieved withouthaving to provide different materials.

Also using different base materials for the first and the second partialregion allows different properties of the respective expanded TPU. Thus,the first and second partial regions may also be provided with differentproperties without having to change parameters of the steaming process.

The first expanded TPU may comprise a first particle size, wherein thesecond expanded TPU may comprise a second particle size that differsfrom the first particle size. The different particle sizes for examplemay provide different cushioning of the first and second TPU. Thedifferent particle size may be achieved by means of different particlesizes of the base material and/or a different steaming process.

In other embodiments, the sole further comprises a reinforcementmaterial as described above.

In further embodiments, one or more partial regions are at leastpartially surrounded by a foil, in particular a plastic foil. The foilmay be bonded to the one or more partial regions in a steaming processfor the one or more partial regions, in particular through a chemicalreaction. By means of using the foil, the properties of the one or morepartial regions may be further differentiated with respect to eachother. In addition, a foil allows further differentiating the externalappearances of the one or more partial regions. Additionally, the foilmay be used in combination with further inner and/or outer sole elementsas described above.

In some embodiments, the partial regions are bonded to each other by asteaming process for the first expanded TPU and/or the second expandedTPU. Also, when using two partial regions with a first and a second TPU,the sole elements may thus be bonded to each other in a labor-saving,fast, and cost-efficient manner. In addition, the precision of thebonding of two partial regions of expanded TPU is particularly highsince the partial regions expand in an almost identical manner and thusthe adaptation of the partial regions to each other is ensuredparticularly well.

In further embodiments, the first partial region comprises a first solelayer and a second partial region comprises a second sole layer. Thus, asole may be provided that comprises different functionalities indifferent sole layers. For example, it may be particularly advantageousto provide a sole layer that is located close to the foot of the wearerof the shoe in a particularly cushioning manner, whereas for example anouter sole layer may be provided with more strength and/orabrasion-resistance.

In certain embodiments, the sole comprises a third sole layer that isfree from expanded TPU. Thus, the sole may be combined with specificproperties of other materials. According to some embodiments, the thirdsole layer is bonded to at least one of the first and the second solelayers in a steaming process for at least one of the first and thesecond sole layers. The third sole layer may for example be an outsolethat comprises high slip-resistance and/or high abrasion-resistance. Theoutsole may comprise non-expanded TPU, in particular transparent TPU.Thus, there are various possibilities for creating designs since thetransparent outsole may be printed on, foils may be arranged on theirback side or they may be colored. Hence, different designs and/orornamentations may be arranged on the outsole.

In further embodiments, the third sole layer is arranged between thefirst and second sole layer. For example, in a first sole layer that isarranged close to the shoe upper a high cushioning may be provided inorder to achieve a pleasant wearing comfort. At the same time, in asecond sole layer, which is arranged such that it faces the bottom areaof the sole, a high elasticity may be provided. Both sole layers may bestabilized by means of the third sole layer.

In some embodiments, the first partial region comprises a first surfaceregion and the second partial region comprises a second surface region.Thus, the different possible advantageous properties of expanded TPU maybe combined advantageously in a first and a second surface region.

In certain embodiments, the first surface region is arranged essentiallyon the medial side of the sole. Thus, for example the elasticity may beincreased in that region. This facilitates fast lateral movements of thefoot since that region of the sole often has to bear particular loadswhen fast lateral movements are carried out. Returning the energy thatis used for the loading by means of high elasticity when cushioning theload is thus particularly desirable in that region.

In further embodiments, the first surface region is arranged essentiallyon the medial side of the sole and the second surface region isessentially arranged on the lateral side of the sole. Thus, lateralmovements of the foot may be supported and/or balanced particularlywell.

In further embodiments, at least one of the partial regions comprisingTPU and/or the foil comprising TPU may be colored with a colorcomprising liquid TPU to provide the advantageous effects discussedabove.

In certain embodiments, the sole is constructed in such a way that thesole has a weight of less than about 100 g. By providing such a lightsole, an extremely light-weight shoe may be provided that is beneficiale.g. to the performance of an athlete wearing the shoe. In otherembodiments, the complete shoe has a weight of less than about 100 g.

In yet other embodiments, an insole for arrangement within an upper of ashoe, in particular a sports shoe, comprises expanded TPU.

By means of providing an insole with expanded TPU, insoles may beequipped with the specific properties of this material. The expanded TPUis particularly suitable for insoles since insoles require particularlygood cushioning properties as well as elastic properties. Since theproperties of the expanded TPU, as already discussed, are variable,insoles with different specifications may be provided that may beexchanged easily. For example, a soft insole may be used for practicingpurposes and a harder sole may be used for competitions. The respectivedesired properties may thus be achieved by simply inserting a suitableinsole made from expanded TPU. The properties of the insole may in thiscontext be varied without having to vary the thickness of the insole.The extensive temperature-independence of the properties of expanded TPUrenders expanded TPU advantageous particularly for insoles. In spite ofwarming the insole to the body temperature of the foot during the courseof time, the properties of the insole remain constant.

By means of using expanded TPU for an insole, for example, enoughcushioning functionality may be provided such that an additionalintermediate sole is not necessary. Hence, the manufacturing of a shoemay be simplified. Moreover, the user therefore has the possibility tochange the functionality that would normally be provided by anintermediate sole—which is not exchangeable—by means of changing theinsole.

In addition, by means of expanded TPU a particularly elastic insole maybe provided that returns the energy used for compressing the insole withonly minimal losses when springing back. Further, by means of expandedTPU a particularly light insole may be provided.

In certain embodiments, the insole is at least partially surrounded by afoil, in particular a plastic foil. In that way, as already explained,the functionality of the expanded TPU as well as its external appearanceand its texture may be changed. In the context of insoles in particularalso a change of the haptics of the insole is of advantage. It is alsoof importance that the effect of for example water or dirt on the insolemay be affected by the foil. The foil may further be used in a number ofadditional ways described above to provide the further benefits alreadydiscussed.

In other embodiments, the insole may further comprise a textilereinforcement material, e.g. to increase the stability of the sole.

In further embodiments, the insole and/or the foil may be colored with acolor comprising liquid TPU.

In further embodiments, a shoe, in particular a sports shoe, comprises asole according to one of the aforementioned embodiments.

The shoe may comprise an upper wherein the sole is bonded to the upperin a steaming process without gluing means. Thus, a gluing or sewing ofthe shoe sole to the upper is avoided.

In further embodiments, a method for manufacturing a shoe sole, inparticular a shoe sole for a sports shoe comprises loading a mold withan expanded TPU for a first surface region. In addition, the mold isloaded with a material that is free from expanded TPU for a secondsurface region. Moreover, steam is fed to the expanded TPU. In that way,the expanded TPU may be melted and bonded to a foam structure. By meansof this method an advantageous sole may be manufactured efficiently. Inparticular, the method allows a large degree of automation and at thesame time design freedom. An arbitrary first surface region withexpanded TPU and a surface region free from expanded TPU may be bondedto form a sole in one manufacturing method. Steps such as cutting orgluing are unnecessary.

In other embodiments, a method for manufacturing a shoe sole, inparticular a shoe sole for a sports shoe, is provided, comprising aloading of a mold with a first expanded TPU for a first partial regionand a loading of the mold with a second expanded TPU for a secondpartial region. The first and the second expanded TPU comprise differentdensities and/or different base materials. In addition, steam is fed tothe first and second expanded TPU. Thus, soles that include theadvantageous material properties of expanded TPU and also enable varyingthe properties of the expanded TPU within the sole may be provided in anefficient manufacturing process.

In some embodiments, the expanded TPU and/or the first and the secondexpanded TPU comprise particles. These particles may be loaded into amold in a simple manner. They may be compressed in the mold and recastinto a continuous foam structure. The particle shape allowsmanufacturing expanded TPU with different properties in a simple manner.

In some embodiments, the method further comprises the partial melting ofthe surface of the particles. In these embodiments, the particles areheated by means of applying steam, wherein the surface of the particlespartially melts, such that the particles may chemically bond to eachother. This leads to a foam structure of the expanded TPU.

In other embodiments, the expanded TPU or the first and/or the secondexpanded TPU is compressed after the loading of the mold. Thedensification may be provided by a reduction of the volume of the mold,for example by closing the mold to a predetermined extent. Therein, thedensity may be varied, which allows different weights and stabilities ofan expanded TPU. For example, the density may be varied by means ofvarying the extent to which the mold is opened prior to the loadingwhile at the same time the geometry is maintained. The more the expandedTPU is compressed, the more stable it will for example be in its finalstate. Moreover, the densification may be locally varied. Thus, by meansof densification, a desired locally-varying stability of the expandedTPU may be achieved. In that way, a large design freedom and variabilityis obtained with which different expanded TPU may be provided when usingonly a single base material.

In yet other embodiments, the loading of the expanded TPU or the firstand/or the second expanded TPU is carried out under pressure. ExpandedTPU is thus loaded into the mold in a pressurized manner. Thus, a fastermanufacturing method may be provided.

In further embodiments, a method for manufacturing a shoe sole furthercomprises a relaxation of the expanded TPU or the first and secondexpanded TPU. Subsequent to loading the mold with compressed, expandedTPU, the pressure within the mold is relaxed. In these embodiments, thecompressed, expanded TPU particles re-expand essentially to theiroriginal size. Thus, a continuous foam structure may be provided.

In further embodiments, a method for manufacturing a shoe soleadditionally comprises a curing of the expanded TPU or the first andsecond expanded TPU. By means of a curing step, the structure of theexpanded TPU may be stabilized.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following detailed description, embodiments of the invention aredescribed referring to the following figures:

FIG. 1 a is a graph comparing long-term stability properties of expandedTPU and EVA.

FIG. 1 b is a graph comparing energy loss properties of expanded TPU andEVA at different temperatures.

FIG. 1 c is a graph comparing influence of temperature on performance ofexpanded TPU and EVA.

FIG. 2 a is an exploded perspective view of a shoe with a first surfaceregion and a second surface region, wherein the first surface regioncomprises an expanded TPU and wherein the second surface region is freefrom expanded TPU according to certain embodiments of the presentinvention.

FIG. 2 b is a partial perspective view of the shoe of FIG. 2 a.

FIG. 2 c is a bottom perspective view of the shoe of FIG. 2 a.

FIG. 3 a is a side view of a shoe comprising a sole with a first surfaceregion and a second surface region, wherein the first surface regioncomprises an expanded TPU and wherein the second surface region is freefrom expanded TPU according to certain embodiments of the presentinvention.

FIG. 3 b is an exploded view of the sole of the shoe of FIG. 3 a.

FIG. 4 a is a bottom view of a shoe comprising a sole with a firstsurface region and a second surface region, wherein the first surfaceregion comprises an expanded TPU and wherein the second surface regionis free from expanded TPU according to certain embodiments of thepresent invention.

FIG. 4 b is a side view of the shoe of FIG. 4 a.

FIG. 5 a is a bottom view of a sole for a shoe, in particular a sportsshoe, comprising a first surface region and a second surface region,wherein the first surface region comprises an expanded TPU and whereinthe second surface region is free from expanded TPU according to certainembodiments of the present invention.

FIG. 5 b is a side view of the sole of the shoe of FIG. 5 a.

FIG. 6 is a perspective view of an example for an expanded TPU with afunctional element, wherein the expanded TPU surrounds at least twoopposing surface areas of the element according to certain embodimentsof the present invention.

FIG. 7 a is an exploded perspective view of a shoe comprising a solewith a first surface region and a second surface region, wherein thefirst surface region comprises an expanded TPU and wherein the secondsurface region is free from expanded TPU according to certainembodiments of the present invention.

FIG. 7 b is a side view of the shoe of FIG. 7 a.

FIG. 8 a is a perspective view of a shoe comprising a sole with a firstpartial region which comprises a first expanded TPU and a second partialregion, which comprises a second expanded TPU according to certainembodiments of the present invention.

FIG. 8 b is a bottom view of the shoe of FIG. 8 a.

FIG. 9 a is a side view a shoe comprising a sole with a first partialregion which comprises a first expanded TPU and a second partial regionwhich comprises a second expanded TPU according to certain embodimentsof the present invention.

FIG. 9 b is a rear view of a portion of the shoe of FIG. 9 a.

FIG. 10 a is an exploded perspective view of a shoe comprising a solewith a first partial region which comprises a first expanded TPU and asecond partial region which comprises a second expanded TPU according tocertain embodiments of the present invention.

FIG. 10 b is a top view of the sole of the shoe of FIG. 10 a.

FIG. 11 a is a perspective view of a foil which may at least partiallysurround at least a surface region and/or at least a partial region ofexpanded TPU according to certain embodiments of the present invention.

FIG. 11 b is an exploded perspective view of a sole comprising a foilaccording to certain embodiments of the present invention.

FIG. 12 a is a bottom view of an insole for arrangement within an upperof a shoe, wherein the insole comprises expanded TPU according tocertain embodiments of the present invention.

FIG. 12 b is a top view of the insole of FIG. 12 a.

FIG. 12 c is a side view of the insole of FIG. 12 a.

FIG. 13 a is a bottom view of an insole for arrangement within an upperof a shoe, wherein the insole comprises expanded TPU and the insole ismanufactured from expanded TPU area-wide according to certainembodiments of the present invention.

FIG. 13 b is a top view of the insole of FIG. 13 a.

FIG. 13 c is a side view of the insole of FIG. 13 a.

FIG. 13 d is a bottom view of an insole for arrangement within an upperof a shoe, wherein the insole comprises expanded TPU and the insole ismanufactured from expanded TPU area-wide according to certainembodiments of the present invention.

FIG. 14 a is a diagram illustrating a method of manufacturing a sole fora shoe according to certain embodiments of the present invention.

FIG. 14 b is a diagram illustrating a method of manufacturing a sole fora shoe according to certain embodiments of the present invention.

FIG. 14 c is a diagram illustrating a method of manufacturing a sole fora shoe according to certain embodiments of the present invention.

FIG. 15 a are side views of a mold in an open state and closed state,respectively, for use in various embodiments of a method formanufacturing a shoe sole, according to certain embodiments of thepresent invention.

FIG. 15 b are side views of a mold in an open state and closed state,respectively, for use in various embodiments of a method formanufacturing a shoe sole, according to certain embodiments of thepresent invention.

FIG. 15 c are side views of a mold in an open state and closed state,respectively, for use in various embodiments of a method formanufacturing a shoe sole, according to certain embodiments of thepresent invention.

FIG. 15 d are side views of a mold in an open state and closed state,respectively, for use in various embodiments of a method formanufacturing a shoe sole, according to certain embodiments of thepresent invention.

FIG. 15 e is a perspective view of a mold in an open state for use invarious embodiments of a method for manufacturing a shoe sole, accordingto certain embodiments of the present invention.

FIG. 16 is a diagram illustrating a method of manufacturing a sole for ashoe according to certain embodiments of the present invention.

FIG. 17 is a bottom view of a shoe comprising a foil that acts as ameans to attach outer sole elements to the midsole according to certainembodiments of the present invention.

FIG. 18 a is a bottom perspective view of a sole comprising a first anda third surface region comprising expanded TPU that are surrounded by asecond surface region comprising expanded PP and an inner sole element,wherein all three surface regions are at least partially covered with afoil and the inner sole element is attached to the surface regions bythe foil according to certain embodiments of the present invention.

FIG. 18 b is another perspective view of the sole of FIG. 18 a.

FIG. 19 a is a bottom perspective view of a sole comprising a first anda third surface region comprising expanded TPU that are surrounded by asecond surface region comprising EVA and an inner sole element, whereinall three surface regions are at least partially covered with a foil andthe inner sole element is attached to the surface regions by the foilaccording to certain embodiments of the present invention.

FIG. 19 b is another perspective view of the sole of FIG. 19 a.

FIG. 20 a is a top perspective view of a sole, in particular a sole fora heat insulating shoe such as a winter shoe or a hiking shoe,comprising a first surface region comprising expanded TPU arranged inthe forefoot region of the sole, and a second surface region, as well asa partial region comprising a heel insert, comprising a highly viscoseEVA based compound according to certain embodiments of the presentinvention.

FIG. 20 b is a bottom perspective view of the sole of FIG. 20 a.

FIG. 20 c is a side perspective view of the sole of FIG. 20 a.

FIG. 21 is a diagram illustrating the heat insulating properties ofexpanded TPU compared to EVA.

FIG. 22 are multiple side views of a sole for a shoe, in particular awinter shoe or a hiking shoe, according to certain embodiments of thepresent invention.

DETAILED DESCRIPTION

The subject matter of embodiments of the present invention is describedhere with specificity to meet statutory requirements, but thisdescription is not necessarily intended to limit the scope of theclaims. The claimed subject matter may be embodied in other ways, mayinclude different elements or steps, and may be used in conjunction withother existing or future technologies. This description should not beinterpreted as implying any particular order or arrangement among orbetween various steps or elements except when the order of individualsteps or arrangement of elements is explicitly described.

In the subsequent detailed description, presently preferred embodimentsof the present invention are described with respect to sports shoes.However, it is emphasized that the present invention is not limited tothese embodiments. For example, the present invention may also beapplied to shoes for work, leisure shoes or other shoes.

FIGS. 1 a-c show a comparison of the properties of expanded TPU (“eTPU”)and foamed EVA.

FIG. 1 a shows the long-term stability of both materials. It may be seenthat expanded TPU, when compared to foamed EVA, is compressed about 60%less for the same long-term load of approximately 100,000 compressioncycles. Thus, expanded TPU is more dimensionally stable. Even whenforces are applied continuously, it is only compressed to a small extentand therefore, to a large degree, maintains its shape. Thus, it is verywell suited for soles that are exposed to such high long-term loadings.By means of the longevity of expanded TPU, waste due to worn-out shoesand shoe soles, respectively, is also avoided in the long run. Thus,more environmentally-friendly shoes may be provided. As alreadymentioned, expanded TPU is very durable and it is also very soft. Itscushioning range is up to about 80%, meaning that for example a 10 mmthick sole may be compressed down to about 2 mm during usage. Thematerial therefore provides good cushioning to, e.g., a runner and therunner has to use less energy during running, resulting in improvedrunning efficiency.

FIG. 1 b shows the energy loss of EVA and expanded TPU for differenttemperatures. The energy loss in percent indicates the amount of energyused for compressing the material that is lost during the subsequentexpansion, which for example is converted to heat. This fraction of theenergy is not returned, for example, to a sprinter when the sole springsback after hitting the ground and compressing. Therefore, an energy lossthat is as small as possible is usually desirable. As is shown in FIG. 1b, the energy loss is substantially smaller in expanded TPU as comparedto foamed EVA in all typical temperature ranges. The energy loss ofexpanded TPU is reduced compared to foamed EVA by at least about 25% at25° C. At 0° C., it is reduced by at least about 40% and at −20° C., itis reduced by at least about 28%.

FIG. 1 c shows the force that has to be applied for a predeterminedcompression of expanded TPU and foamed EVA in a temperature-dependentcomparison. It may be seen that the curve 110 for expanded TPU isessentially constant in a temperature range from about −20° C. to about+30° C. Therefore, the compressibility of expanded TPU is essentiallytemperature-independent. Further, FIG. 1 c shows that expanded TPU stayssofter than EVA (cf. curve 120 for EVA) in all temperature ranges, i.e.it may have a stronger cushioning effect. In particular, expanded TPU,in contrast to EVA, avoids the disadvantage of becoming hard at lowtemperatures. Furthermore, since the material characteristics ofexpanded TPU are temperature-independent (within the temperature rangeof interest for footwear), expanded TPU is more durable and maintainsits good performance characteristics in every situation. Expanded TPUtherefore avoids the disadvantage of becoming hard, stiff, brittle ordamaged.

Furthermore, FIG. 21 shows the results of measurements of the heatinsulating properties of expanded TPU (cf. measurements 2110 and 2120)compared to EVA (cf. measurements 2130 and 2140). Measurement 2110relates to expanded TPU manufactured with approximately a 10 mm crack,wherein the crack is the opening of the mold while filling and beforecompression and steaming of the expanded TPU (for more details on themanufacturing process, cf. below). Measurement 2120 relates to expandedTPU manufactured with approximately a 14 mm crack. Measurement 2130relates to compression molded EVA material, and measurement 2140 relatesto injection molded EVA material. As can be seen from FIG. 21,independent from manufacturing details, expanded TPU provides up toabout 30% better heat insulation as EVA. This is based on the fact thatevery particle of the expanded TPU captures air and a sole comprisingexpanded TPU therefore provides various barriers against thermalexchange leading to better heat insulating properties. Another relatedadvantage of the use of particles comprising expanded TPU formanufacturing a heat insulating sole is that these particles do not haveto be arranged in a particular direction or pattern in order to formsuch thermal barriers. Instead, the particles can essentially bearranged randomly, greatly simplifying the production process.

The extensive temperature-independence of the mechanical properties ofexpanded TPU and the better heat insulating properties as compared toother materials leads to a new variety of using expanded TPU as solematerial. Besides the known fields of indoor and summer sports, newpossible applications for example in the field of winter sports or novelshoe concepts such as running shoes for the winter season may be found.Expanded TPU may be used irrespective of winter or summer seasons andindependent from regional circumstances. Thus, substantially moreversatile shoes may be provided.

FIG. 2 a shows a principle for certain embodiments of a shoe 200 thatcomprise an upper 220 and a sole 210. The sole comprises a first surfaceregion 211, wherein the first surface region 211 comprises an expandedTPU.

The first surface region 211 is arranged in the heel region, inparticular, in the region below the calcaneus. In addition, the sole 210comprises a third surface region 2111, which is arranged in the forefootregion. The first surface region 211 and the third surface region 2111,respectively, ensure a particularly good cushioning in the heel regionand in the forefoot region. In these regions, in particular in theregion underneath the calcaneus, the first contact to ground is to beexpected for regular running or walking movements. A particularcushioning is therefore desirable in these regions in order to dampenthe impact of the foot hitting the ground. In addition, within theseregions, in particular within the forefoot region, often the lastcontact of the sole with the ground occurs, before the foot is liftedoff of the ground. A particularly elastic cushioning by means of theexpanded TPU is therefore particularly desirable in these regions suchthat the energy that is lost due to the impact of the foot on the groundis recovered when the foot lifts off of the ground. Thus, during theimpact the foot, and therefore for example also the runner duringrunning, only loses a minimal amount of energy.

In other embodiments, a different arrangement of the surface regions211, 2111 may be advantageous. In particular, the sole 210 may, in otherembodiments, also only comprise a first surface region 211 or more thantwo surface regions 211, 2111.

In addition, the sole 210 comprises a second surface region 212, whichis free from expanded TPU. The second surface region 212 is arrangedaround the outer rim of the sole as well as between the forefoot regionand the calcaneus. Especially for quick lateral movements, the outer rimof the sole experiences large loadings. Moreover, for example by meansof supination or overpronation, depending on the wearer of the shoe, alarge loading of the sole may occur at the medial or lateral sides ofthe sole. By means of a second surface region 212 at the outer rim ofthe sole, an increased stability may be provided in that location.Further, by means of arranging the second surface region 212 between theforefoot region and the calcaneus, the stability of the sole as a wholemay be increased. In other embodiments, a different arrangement of asecond surface region 212 may be advantageous.

The second surface region 212 comprises EVA. In other embodiments, thesecond surface region 212, however, may also comprise differentmaterials. In other embodiments, the second surface region comprisesexpanded PP. Expanded PP is an extremely light weight yet stablematerial and the combined use of expanded TPU for the first and thirdsurface regions and expanded PP for the second surface region providesfor an extremely light yet stable sole and shoe with good cushioning andenergy return properties. In some embodiments, the sole has a weight ofless than about 100 g and, in a certain embodiments, the complete shoehas a weight of less than about 100 g.

The second surface region 212 surrounds the first surface region 211 andthird surface region 2111. This provides the surface regions 211 and2111 with additional stability. Moreover, by surrounding the surfaceregions, the extension of the first and third surface regions is limitedand hence their cushioning is restricted.

In certain embodiments, the first surface region 211 and the thirdsurface region 2111 may comprise a first and a second expanded TPU,respectively. Thus, different functionalities may be provided forexample in the forefoot region and the heel region. For example, thefirst surface region 211 may comprise a first expanded TPU with a higherstrength such that a higher strength is provided in the heel region.

FIG. 2 b shows a view of certain embodiments of a shoe 201 that ismodified relative to the shoe 200. In particular, in these embodiments,the sole 210 comprises an additional outsole 213. In some embodiments,the outsole 213 provides the sole 210 with an improved slip-resistanceand/or abrasion-resistance. In other embodiments, the outsole 213comprises rubber or TPU. In these embodiments, the outsole may not bearranged area-wide. Thus, the abrasion-resistance and/or slip-resistanceof the sole may be optimized, wherein at the same time the weight of thesole is minimized. In some embodiments, the outsole provides the solewith a specific profile. In other embodiments, the shoe does notcomprise an outsole or an outsole that is designed differently and thatcovers the first surface region 211 partly or entirely.

In further embodiments, different and/or additional layers or partiallayers may be included with the sole. In addition, as shown in FIG. 2 c,the sole 210 comprises a recess 214 for an electronic unit that mayprovide the user of the shoe 201 with functionalities such as speedmeasurement or distance measurement. In certain embodiments, allcomponents of the sole 210 are bonded to each other by means of thesteaming process for the expanded TPU. As a result, no further gluingmeans are necessary in order to connect the parts of the sole 210. Inaddition, the parts may be connected in an automatized and particularlyprecise manner. Hence, a fast, high-quality and cost-effectiveproduction may be provided.

FIG. 2 c shows the region of the first surface region 211 that isarranged underneath the calcaneus in top view. By means of the strongcushioning of the first surface region 211, the latter may be in directcontact with the foot. For example, this may be achieved by means of anopening in a sole of the Strobel type that is arranged on top of thefirst surface region. In FIG. 2 c, the opening is arranged circularly.In other embodiments, however, it may for example also be arrangedannularly or in a star-shaped manner. It may also be possible that slitsare incorporated into the sole of the Strobel type, which also minimizethe tensile force of the sole of the Strobel type in the heel region,similar to an opening therein. Thus, a pleasant wearing comfort may beachieved at the foot. In addition, the extensivetemperature-independence of the cushioning of the first surface region211 allows a direct contact with the foot. No substantial change of thecushioning takes place when the first surface region 211 is warmed tothe body temperature of the foot. In certain embodiments, midsoles orinsoles may be entirely unnecessary.

FIG. 3 a shows further embodiments for a shoe 300. It comprises an upper320 and a sole 310. The sole 310 comprises a first surface region 311,wherein the first surface region 311 comprises an expanded TPU. In thefront toe region, the shoe 300 also comprises a second surface region312, which is free from expanded TPU. Thus, an increased strength of thesole may be provided in the toe region. This is particularly desirablesince, especially in the region of the toe tips, a sole that is too softand a slipping of the shoe associated therewith may be perceived asdispleasing and for example may lead to a formation of blisters on thefoot. In the remaining regions of the sole, a particularly largecushioning is achieved by means of a first surface region 311. Therein,the thickness of the first surface region 311 increases from the toeregion towards the heel region. Thus, the sole provides an increasedstrength in the heel region. On the one hand, this increased strengthprovides the sole with increased stability. On the other hand, thecushioning properties of the first surface region 311 are adapted to thelarger forces that occur in the heel region. There, the larger forceslead to a larger loading as compared to the forefoot region. The dampingis equally adapted across the entire area of the first surface region311 via the increased thickness of the first surface region in the heelregion.

In addition, the sole 310 optionally comprises an outsole 313. In someembodiments, the outsole comprises rubber or non-expanded TPU. Theoutsole 313 provides the sole 310 with additional slip-resistance andabrasion-resistance. The outsole 313 may be bonded to the first surfaceregion 311 in a steaming process for the expanded TPU. In someembodiments, an outsole is not included.

When compared to sole 210 of FIG. 2 b, it can be seen from FIG. 3 a thatit is not necessary to arrange the second surface region 312 along theouter rim of the sole. In some embodiments of sole 310, the firstsurface region 311 comprises a large part of the outer rim of the sole.In these embodiments, the expanded TPU comprises a strength that is ableto resist the loading at the outer rim.

FIG. 3 b shows a top view of the first surface region 311. Moreover, theintermediate sole 314 can be seen. The first surface region 311 isarranged such that it may be precisely fitted into the intermediate sole314. In other embodiments, the intermediate sole 314, which for examplecomprises EVA, may comprise a different shape, and the first surfaceregion 311 may correspondingly be designed differently. The firstsurface region 311 and the intermediate sole 314 may be bonded to eachother in a steaming process for the expanded TPU. The intermediate sole314 is in particular arranged in the second surface region 312 to whichit provides increased stability. Moreover, the intermediate sole 314 isalso arranged along the outer rim of the sole such that the stability isincreased in that location. In some embodiments, the intermediate soleis an intermediate element, such as a frame. In certain embodiments, itmay comprise non-expanded TPU or essentially consist of non-expandedTPU, which optimizes the bonding to expanded TPU and also improves thebonding to the upper. In other embodiments, the upper is directly sewedto the TPU intermediate element such that no gluing means are required.

FIG. 4 a shows certain embodiments of a sole 410 for a shoe 400. Itcomprises a first surface region 411, wherein the first surface region411 comprises an expanded TPU, and a second surface region 412, which isfree from expanded TPU. Moreover, the sole 410 optionally comprises anoutsole 413. Further, the sole 410 optionally comprises a recess for anelectronic unit. In addition, the sole 410 optionally comprises a thirdsurface region 4111 and a fourth surface region 4112, which compriseexpanded TPU.

The first surface region 411 is located in the forefoot region. Thethird surface region 4111 is located medially as well as laterallybetween the forefoot region and the heel region. Moreover, the fourthsurface region 4112 is located in the heel region. Thus, a particularlyhigh flexibility of the sole 410 and thus a pleasant wearing comfort isprovided in the forefoot region, midfoot region, and the heel region. Inthe remaining regions of the sole 410, the second surface region 412 isarranged. In particular, the arrangement along the outer rim of the sole410 in the forefoot and heel regions increases the stability of the soleto suitable extent. The second surface region 412 comprises EVA but mayalso comprise different and/or further materials.

In certain embodiments, the outsole 413 does not entirely cover thefirst surface region 411. The outsole 413 may provide the sole with aspecific profile. For example, in some embodiments, the first surfaceregion 411 is provided with a continuous outsole. In other embodiments,the shoe does not comprise an outsole 413 or a differently designedoutsole 413. In particular, for indoor shoes, the expanded TPU alreadyprovides a sufficient slip-resistance such that this aspect does notrequire an additional outsole 413.

In order to increase the abrasion-resistance and/or the slip-resistanceof the surface of the first surface region, it may be modified, incertain embodiments, by means of suitable surface treatment instead ofproviding it with an outsole. The surface of a surface region and/or apartial region of expanded TPU may be partially melted and/or embossedand/or treated by means of a laser. Moreover, the surface may bemanufactured in a correspondingly designed shape that provides anincreased abrasion-resistance and/or slip-resistance. Further, differentmaterials, for example particles of different materials, which increasethe abrasion-resistance, may be included in the manufacturing process inregions close to the surface of the expanded TPU.

FIG. 4 b shows a sole 410 on an upper 420. FIG. 4 b illustrates how thethird surface region 4111 and the second surface region 412 are locatedalong the outer rim of the sole. In the forefoot and heel regions, thesecond surface region 412 is arranged along the outer rim where itincreases the stability of the sole. In the region that liestherebetween, an increased flexibility of the sole is desirable in orderto support the natural rolling of the foot. Correspondingly, the secondsurface region 412 is not arranged there. Instead, a surface region4111, which comprises expanded TPU, is arranged there. Thus, anincreased flexibility may be provided there.

In addition, the thickness of the surface region 4111 increases from theforefoot region towards the heel region. Thus, the functionality of thesurface region 411 may be gradually adapted to the differentrequirements in the specific regions.

In some embodiments, the surface regions 411, 4111, and 4112 compriseonly one expanded TPU. In other embodiments, at least the first surfaceregion 411 and the third surface region 4111 comprise a first and asecond expanded TPU, respectively.

FIG. 5 a shows further embodiments of a sole 510. It comprises a firstsurface region 511, wherein the first surface region 511 comprises anexpanded TPU, as well as a second surface region 512, which is free fromexpanded TPU. The first surface region 511 is arranged along the outerrim of the sole, wherein the lateral outer rim between heel region andforefoot region is not covered by the first surface region 511. Thefirst surface region 511 is optionally strengthened with an outsole 513,which increases the slip-resistance and/or abrasion-resistance of thesole 510. The outsole 513 may only cover a part of the first surfaceregion 511. In some embodiments, the outsole 513 comprises rubber orTPU. Optionally, the sole 510 also comprises a partial region 514,which, in some embodiments, provides the sole 510 with increasedstability. In some embodiments, the partial region 514 comprises EVA.However, the partial region 514 is not included in all embodiments. Bymeans of the increased strength of the expanded TPU, in someembodiments, the partial region 514 may not be necessary. In particular,the sole may thus be manufactured in a material-saving manner and, thus,a lighter sole may be provided. At the same time, the large elasticityof the TPU ensures that the energy is optimally returned to therunner/walker when the sole springs back.

Compared to many other materials, for example EVA, a first surfaceregion 511 may be more precisely manufactured by means of expanded TPUsince this material only slightly expands during the steaming process.Hence, smaller structures may be manufactured, which in total allows afunctionality that is adjusted in an improved manner. Further, thisenables a minimalistic design such that a large amount of material maybe saved since only small amounts of expanded TPU that are reduced tothe required minimum are used. Thus, as shown in some embodiments ofsole 510 (without the optional partial region 514), a large secondsurface region 512 of the sole may remain free. In particular, the firstsurface region 511 may comprise recesses, such as large-area recesses.

In certain embodiments, the first surface region 511 may also serve tomodify the functionality of the partial region 514. In theseembodiments, the first surface region 511 is not located in the entireregion of the partial region 514. Thus, the functionality of the partialregion 514 is changed only locally. For example, the cushioning islocally increased. From an opposite point of view, the partial region514 may increase the stability of the first surface region 511, whichcomprises expanded TPU. According to some embodiments, the sole 510comprises a sole plate. The latter may provide the sole with increasedstability. The sole plate may connect the sole to the upper. The firstsurface region 511 and the optional partial region 514 may be arrangedunderneath the sole plate.

FIG. 5 b shows slightly modified embodiments of sole 501, which ismanufactured on a sole plate 516, similar to sole 510. The sole plate516 ensures the basic stability of the sole and serves to distribute theforces that act on the sole. Moreover, it may serve as a carrier for amultitude of functional elements that are bonded to each other with thesteaming process for the TPU. The thickness of the first surface region511 increases from the toe region towards the heel region. Thus, thestrength of the sole is gradually adjusted to the expected forces in therespective regions.

Moreover, FIG. 5 b shows that the first surface region 511 may also bedesigned such that the region 515 between forefoot region and heelregion is free from the first surface region 511. Thus, the flexibilityof the sole may be optimized to support the natural rolling of the foot.Depending on the foot type of the wearer of the shoe, the first surfaceregion 511 may also comprise a medial or lateral outer rim of the solesuch that the flexibility of the sole is adjusted to a supination oroverpronation.

FIGS. 20 a-c show other embodiments of a sole 2000 for a shoe, inparticular a heat insulating shoe, for example a winter shoe or a hikingshoe. The sole 2000 is also particularly well suited for a shoe used inuneven terrain. The sole 2000 comprises a first surface region 2010comprising expanded TPU arranged in the forefoot region, surrounded by asecond surface region 2020. In other embodiments, the second surfaceregion 2020 is free from TPU. The sole 2000 further comprises a partialregion 2030 arranged in the heel region. In some embodiments, thepartial region 2030 comprises a heel insert comprising an elastomercompound, for example a highly viscose EVA based compound.

FIG. 22 shows further embodiments 2200 of soles for the use in shoes, inparticular outdoor shoes. According to certain embodiments, a sole 2200a includes the profile of a sole comprising a surface region 2220 a,which may be free from TPU, and a first partial region 2210 a arrangedin the forefoot region, as well as a second partial region 2230 aarranged in the heel region. In some embodiments, the first and secondpartial regions 2210 a and 2230 a comprise expanded TPU.

In some embodiments, a sole 2200 b includes the profile of a solecomprising a first surface region 2210 b and a second surface region2220 b, wherein the first surface region 2210 b is arranged in theforefoot region and comprises expanded TPU, and wherein the secondsurface region 2220 b may be free from TPU. The sole further comprises apartial region 2230 b arranged in the heel region, which may alsocomprise expanded TPU. In other embodiments, a sole 2200 c of a soleincludes a first surface region 2210 c arranged in the forefoot regionand comprising expanded TPU as well as a second surface region 2220 cfree from TPU. The sole 2200 c further comprises a partial region 2230 carranged in the heel region of the sole comprising an elastomercompound, for example a highly viscose EVA based compound. In furtherpreferred embodiments, the surface regions 2220 a, 2220 b, and 2220 csurround the other surface regions and/or partial regions of the sole.

The use of expanded TPU for a surface region and/or a partial regionarranged in the forefoot region of the foot allows for a high amount ofenergy return to the wearer of the shoe, thus improving performance. Ifused as a surface region, the expanded TPU can at the same time providea better feel of the ground and, combined with the good heat insulatingproperties of the expanded TPU as shown in diagram 2100 of FIG. 21,increase the overall comfort of the shoe, in particular a winter shoe ora hiking shoe. The use of an elastomer compound, for example a highlyviscose EVA based compound, as a heel insert in certain embodiments,helps to absorb the shock energy delivered through the wearer's footwhen the foot impacts the ground, thereby helping to prevent injuriesand overstraining of the wearer's musculoskeletal system. It is to beunderstood that other materials that provide good absorption of theshock energy could also be used for the heel insert instead of or incombination with an elastomer compound.

Furthermore, by providing the heel insert as a partial region ratherthan a surface region and surrounding it with a surface regioncomprising a more stable and resistant material, the wearer's foot isfurthermore well protected from dangerous impediments like stones orglass or other sharp objects when first impacting the ground with thewearer's full weight on the heel during a step, e.g. during running.This helps to further avoid injuries of the wearer's foot, in particularduring outdoor use. The use of a material free of TPU, such as EVA or PPor expanded PP, for a surface region surrounding the othersurface/partial regions of the sole made from expanded TPU and/or anelastomer compound, for example a highly viscose EVA based compound,further helps to improve the stability of the sole, which is especiallyimportant for winter or hiking shoes. It can also help to reduce theweight of the sole, in particular if expanded PP is used.

FIG. 6 shows an example for an expanded TPU 611. The expanded TPU 611may form a surface region or a partial region. A functional element 614,for example a frame element, is integrated into the expanded TPU 611. Aframe element may serve for stabilizing and/or optimizing the correctfit of the shoe. In these embodiments, the functional element 614 isbonded to the expanded TPU 611 in a steaming process for the expandedTPU 611. A partial region of the functional element 614 is entirelysurrounded by the expanded TPU 611, i.e. embedded therein. Other partialregions of the functional element 614 protrude from the expanded TPU611.

In some embodiments, a partial region for a sole is provided thatcomprises expanded TPU, wherein a partial element that is free from TPUis integrated into the expanded TPU. In some embodiments, the functionalelement is integrated such that it is surrounded by the expanded TPUproximate at least two opposing surface areas. In other embodiments, thefunctional element is entirely surrounded by the expanded TPU. Infurther embodiments, the functional element is arranged at a surface ofthe expanded TPU. The functional element may be bonded to the expandedTPU in a steaming process for the expanded TPU.

In other embodiments, the functional element comprises a reinforcementmaterial. The reinforcement material may be a fiber-like reinforcementmaterial or a textile reinforcement material, such as a textilereinforcement material. The textile reinforcement material may be wovenor non-woven, layered or knitted. The reinforcement material can furtherbe non-stretchable; it may be tear resistant and comprise strong fibersor a strong textile material. The use of a textile reinforcement insteadof e.g. a frame element helps to stabilize the sole while at the sametime saving weight in order to provide a lighter shoe. The textilereinforcement material may be attached to at least a part of the one ormore surface and/or partial regions of the sole. In an optional aspectit may also be integrated and/or embedded in the one or moresurface/partial regions. In a preferred aspect, the textilereinforcement material is bonded to the expanded TPU in a steamingprocess for the expanded TPU.

The described embodiments of an expanded TPU with an integratedfunctional element or a reinforcement material may also comprise asecond or several further expanded TPU. For example, the functionalelement and/or reinforcement material may be surrounded by a first and asecond expanded TPU. The first and the second expanded TPU may border ona first and a second surface area of the element, respectively.Moreover, it may comprise further functional elements. As a result, alarge degree of design freedom is obtained. Almost arbitrary functionalelements may be connected with the advantageous properties of expandedTPU. Moreover, a multitude of different design possibilities is at hand.By bonding the elements in a steaming process for one or more TPU, inaddition, a large degree of automation may be achieved. Moreover, alabor-saving, fast, and waste-avoiding manufacturing process ispossible.

FIGS. 7 a-b show further embodiments for a shoe 700 with an upper 720and a sole 710. The sole 710 comprises a first surface region 711, whichcomprises an expanded TPU. In addition, the sole 710 comprises a secondsurface region 712, which is free from expanded TPU. The sole comprisesan intermediate sole 714. Optionally, the sole comprises an outsole 713.

The first surface region 711 is located in the forefoot region. Thus, aparticularly large cushioning may be provided, there. The second surfaceregion 712, which is free from expanded TPU, is arranged in the heelregion. The second surface region 712 may comprise EVA and/ornon-expanded TPU and/or further materials. Thus, an increased strengthof the sole may be provided in the heel region. Hence, the sole may beadapted to the loadings that occur for specific applications. The shoe700, for example, is adapted to cross country running. For that purpose,an increased strength is required in the heel region in order tocounteract a twisting of the foot. On the other hand, particularly inthe forefoot region, an increased cushioning is desirable. This isprovided by means of the first surface region 711, which comprises anexpanded TPU. The large elasticity of the expanded TPU additionallyensures that an optimized energy transmission takes place. When liftingup the toes from the ground and when the first surface region 711springs back in that instance, the energy that is used for compressingthe sole is returned to the runner, with only minimal losses.

The first surface region 711 is moreover raised at the outer rim of thesole. There, it comprises an increased thickness. Alternatively oradditionally, the expanded TPU of the first surface region comprises anincreased thickness at the outer rim of the sole. That way, an increasedstrength may be provided within the first surface region 711 at theouter rim of the sole. This design additionally counteracts a twistingof the foot. Moreover, the thickness of the first surface region 711increases from the toe region towards the heel region and the midfootregion, respectively. Thus, the strength of the sole is adapted to theloadings that typically occur. By means of the expanded TPU, aparticularly gradual adaptation may be achieved. In further embodiments,the first surface region 711 and/or the second surface region 712 mayalso be arranged differently. For example, it may be advantageous insome embodiments to arrange the first surface region 711 in the heelregion and the second surface region 712 in the forefoot region. Thiscould be for example the case for basketball shoes for which anincreased strength in the forefoot region may be desirable.

In some embodiments, the second surface region 712 of the shoe 700 ismainly formed by a part of the intermediate sole 714. The intermediatesole 714 is essentially arranged above the expanded TPU of the firstsurface region 711, and its shape is adapted to the expanded TPU. Inthese embodiments, the intermediate sole 714 is bonded to the expandedTPU in a steaming process for the expanded TPU. The intermediate sole714 may, in other embodiments, also be adapted such that it is arrangedunderneath the expanded TPU of the first surface region 711. In otherembodiments, the intermediate sole 714 is arranged next to the expandedTPU of the first surface region 711 or only partially above or onlypartially below the latter.

Moreover, the shoe 700 optionally comprises an outsole 713, which mayonly partially cover the first surface region 711. The outsole 713 isalso arranged in the second surface region 712. This region of theoutsole may be connected to the outsole on the first surface region 711or it may be arranged as a separate outsole.

FIGS. 8 a and 8 b show a shoe 800 with an upper 820 and a sole 810 witha first partial region 811, which comprises a first expanded TPU, and asecond partial region 812, which comprises a second expanded TPU. Thefirst expanded TPU and the second expanded TPU are manufactured in adifferent steaming process. To this end, at least one parameter, forexample density, temperature, pressure, duration of the expansion, steamsaturation, cooling speed, curing duration, curing temperature etc., ismodified in the manufacturing process of the second expanded TPUcompared to the first expanded TPU. The first and the second expandedTPU may, in certain embodiments, be simultaneously manufactured in thesame mold, wherein the at least one different parameter is appliedlocally. In other embodiments, the first and the second expanded TPU aremanufactured in the same mold subsequently. In other embodiments, thefirst and the second TPU may be manufactured from different basematerials. Moreover, the first and the second TPU may also bemanufactured separately in different molds.

In some embodiments, the first and the second expanded TPU comprisedifferent properties. The different properties may be of a functionalnature. For example, the strength of the second expanded TPU may beincreased as compared to the strength of the first TPU. This may forexample be achieved by applying a larger pressure when manufacturing thesecond expanded TPU. Thus, the second expanded TPU may comprise a higherdensity and a higher strength. Thus, the properties of an expanded TPUmay be varied gradually and they may be combined by means of a firstpartial region and a second partial region. The different properties mayalso be of optical nature, for example they may provide differentcolors.

The first partial region 811 of the sole 810 extends across a largersurface region of the sole 810. However, the sole 810 also comprises asurface region 815 at which the first partial region 811 is not located.In some embodiments, the sole 810 does not comprise any material at allin the surface region 815. In other embodiments, the surface regioncomprises a material that is free from expanded TPU. In yet otherembodiments, the sole 810 does not comprise such a surface region 815.

The second partial region 812 is located in the heel region of the sole.The first partial region 811 comprises corresponding recesses for thispurpose. Thus, the thickness of the sole 810 and thus the strength ofthe sole 810 may be increased by means of a second partial region 812 inthe heel region. This is particularly desirable for running shoes suchas the shoe 800 since, during running, usually particularly large forcesoccur in the heel region. In these embodiments, the second expanded TPUof the second partial region 812 is designed such that it provides alarger strength than the first expanded TPU of the first partial region811. Thus, the strength is particularly increased in the heel region.Moreover, the desired strength may thus be obtained by means of asmaller amount of material. Thus, the sole is lighter and morecost-effective. The second partial region may be bonded to the firstpartial region in a steaming process for the first and/or the secondexpanded TPU. However, also other bonding methods may be used. In someembodiments, a first expanded TPU is up to about 25% softer than asecond expanded TPU. In other embodiments, a first expanded TPU is about25% to 100% softer than a second expanded TPU. In yet other embodiments,the hardness of a first expanded TPU varies with respect to a secondexpanded TPU in the range of about ±150%.

In some embodiments of the sole 810, an additional functional element814 is arranged between the first partial region 811 and the secondpartial region 812. In some embodiments, it provides a cushioning ofshear forces. In other embodiments, the element 814 may also increasethe strength of the sole and/or only serve for optical purposes. Thesole 810 may additionally comprise an optional outsole 813 of rubber orTPU. In other embodiments, the sole 810 does not comprise an outsole orcomprises a different outsole.

In other embodiments of the sole 810, the second partial region 812comprises an EVA. Thus, an increased stability may be provided in theheel region of the sole 810. Further, the second partial region 812 maybe free from expanded TPU.

FIGS. 9 a-b show further embodiments of a shoe 900 with an upper 920 anda sole 910 with a first partial region 911, which comprises a firstexpanded TPU, and a second partial region 912, which comprises a secondexpanded TPU. The first expanded TPU and the second expanded TPU aremanufactured from different base materials. The base materials for thefirst and the second TPU differ from each other by means of at least oneparameter, for example degree of addition of a blowing agent, additionof other materials, and/or particle size of the material. The firstpartial region 911 is arranged above the second partial region 912. Thefirst partial region 911 comprises a first sole layer and the secondpartial region 912 comprises a second sole layer. The first sole layerof the first partial region 911, and second sole layer of the secondpartial region 912, respectively, extend essentially across the entiresole area. In other embodiments, a surface region of the sole 910 may befree from expanded TPU.

In some embodiments, the strength of the second partial region 912 isincreased as compared to the first partial region 911. Thus, in thecontact region with the foot, a large cushioning and a pleasant wearingcomfort may be achieved. By means of the increased strength in thecontact area with the ground, a good stability of the shoe 900 isachieved. In some embodiments, the partial regions 911, 912 differ incolor.

In both partial regions 911, 912, the thickness increases from the toeregion towards the heel region of the sole 910. In addition, thethickness also increases toward the outer rim of the sole 910. Thus, atthe outer rims of the sole 910 and in the heel region, an increasedstrength is provided. In other embodiments, the thickness of the firstand/or the second partial region may be constant or varied in adifferent manner. The sole 910 comprises an optional outsole 913 in theform of a continuous sole layer. The outsole 913 may increase theslip-resistance and/or abrasion-resistance of the sole 910 and/or itswater-repelling properties. In other embodiments, the outsole 913 is notarranged area-wide in order to minimize the weight of the sole 910. Theoutsole 913 may be bonded to the second partial region 912 in a steamingprocess for the second expanded TPU. In further embodiments, no outsole913 is provided.

In other embodiments, the first expanded TPU and the second expanded TPUare manufactured with a different steaming process. In furtherembodiments, the sole 910, in addition, may comprise further partialregions that comprise the first and/or the second and/or furtherexpanded TPU.

In certain embodiments, the outsole 913 may constitute a third partialregion, which comprises an expanded TPU. In particular, the outsole 913may comprise a particularly abrasion-resistive TPU. Thus, the outsolemay be manufactured and/or bonded in the same process as the partialregions 911 and 912. The partial regions may be individually arrangedand may comprise different properties depending on the requirements ofthe shoe and its sole, respectively. They may vary in the base materialused, in their properties (which are determined by the manufacturingprocess), as well as in their geometry. In other embodiments, theoutsole 913 essentially consists of expanded TPU.

In further embodiments, the sole 910, alternatively or additionally tooutsole 913, comprises a third partial region that comprises a thirdsole layer, which is free from expanded TPU. Thus, the sole 910 may beprovided with additional stability. In these embodiments, the third solelayer is arranged between the first and the second sole layer of thefirst and the second partial regions 911, 912. That way, the first andthe second expanded TPU may be separated easily such that for example animproved manufacturing of the first and the second expanded TPU in asteaming process may be achieved.

In other embodiments, the sole 910 is bonded to the upper 920 in asteaming process for the first partial region 911. No additional fixingmeans are required. In these embodiments, the sole 910 may also beattached to the upper 920 by means of other fixing means. The upper maycomprise knit materials, woven materials, non-woven materials, materialscomprising layered fibers and/or fabrics, and/or elastomer compounds.The upper may be provided as one integral piece or it can compriseseveral elements. The upper can further comprise a frame structure, oneor more heel counters, one or more closure systems and essentially anyother element.

FIGS. 10 a-b show further embodiments for a shoe 1000 comprising anupper 1020, and a sole 1010 comprising a first partial region 10111,which comprises a first expanded TPU, a second partial region 10112,which comprises a second expanded TPU, and an optional third partialregion 10113, which comprises a third expanded TPU.

The first, second and third expanded TPU is each made from a differentbase material. The expanded TPU differ in their particle sizes. Therein,the strength of the TPU is, by trend, higher, for smaller particlesizes. In other embodiments, the different particle sizes may also beachieved by means of using a different steaming process.

In certain embodiments, the partial regions are bonded to each other ina steaming process for the first and/or second and/or third TPU. Forexample, the first, second and third TPU may be manufactured at the sametime. Thus, in one manufacturing step different partial regions of asole with different advantageous material properties may be manufacturedand bonded. As a result, a locally adapted sole may be manufacturedquickly, precisely and cost-effectively.

The partial regions 10111, 10112, 10113 are parts of the sole element1011. Optionally, the sole 1010 in addition comprises an outsole 1013that surrounds the sole element 1011 from below as well as laterally. Inother embodiments, the outsole may be arranged differently. The outsole1013 may be directly bonded to the upper 1020. The outsole may be ahousing made of TPU, EVA, rubber and/or foil.

The partial regions 10111, 10112, 10113 are arranged longitudinallyalong the sole, wherein the first partial region 10111 may be arrangedlaterally, the third partial region 10113 may be arranged medially andthe second partial region 10112 may be arranged therebetween. Thestrength increases from the first partial region 10111 via the secondpartial region 10112 towards the third partial region 10113. Thus, forexample the strength of the sole 1010 may be adapted to anoverpronation. In other embodiments, the strength of the sole may alsobe adapted to a supination. Then, the strength of the sole 1010increases from medially to laterally. However, a variety of furtherembodiments of the first partial region 10111, the second partial region10112, and the optional third partial region 10113 may be provided.Moreover, alternatively or additionally, further partial regions, whichcomprise a first and/or a second and/or further expanded TPU, may beprovided. Moreover, also the thickness of the partial regions may vary.As a further variation, the partial regions may also be arrangedtransversely, diagonally or in zones as well as in an overlappingmanner. As yet other embodiments, the expanded TPU materials used forthe one or more partial regions may change in a direction from front toback or in a combined direction from front to back and from the medialto the lateral side.

FIG. 11 a shows a plastic foil 1100 with which a partial region and/or asurface region made of expanded TPU may be surrounded at leastpartially. Thus, the expanded TPU may be provided with a specifictexture, haptics and/or color. Moreover, the lifetime of the surfaceregion and/or partial region may be increased. The plastic foil 1100 forexample prevents water or dirt from acting on the expanded TPU such thatit is attacked to a smaller extent. In addition, the plastic foil 1100may also influence the functionality of the expanded TPU. For example,the foil 1100 may comprise a larger tensile strength than the expandedTPU. Thus, the foil may limit the expansion of the expanded TPU whenspringing back after shocks. Moreover, the foil 1100 may also limit thecompression of the expanded TPU in case it for example fully surroundsthe expanded TPU. The plastic foil 1100 may be manufactured from avariety of materials. For example, the foil may comprise a TPU. By meansof such a foil, an optimized chemical bond between the foil and theexpanded TPU may be achieved. In some embodiments, the foil essentiallyconsists of TPU. In other embodiments, the foil comprises PA,polycarbonate and/or carbon fiber.

In certain embodiments, the foil 1100 is bonded to the expanded TPU in asteaming process for the latter, for example in the form of a surfaceregion or a partial region. In other embodiments, the foil is bonded tothe expanded TPU after a steaming process for the expanded TPU, forexample wrapped around the expanded TPU. In further embodiments, alsoany other functional element of the sole may be manufactured from such afoil and integrated into the manufacturing process of the sole.

In some embodiments, the foil 1100 serves for shaping purposes. ExpandedTPU may be arranged within, outside of or around the foil. The foil mayserve as carrier material for elements such as for example a torsion baror other elements that are to be connected to the expanded TPU or thatare to be fully surrounded by expanded TPU. In other embodiments, thefoil is pre-formed in a deep-drawing process. The foil may be deep-drawnor pressed or injected.

FIG. 11 b shows certain embodiments of a sole 1110. It comprises a firstpartial region, which comprises an expanded TPU. A surface region of thesole in the toe region is free from expanded TPU. In addition, the sole1110 comprises an outsole 1113, which may comprise rubber or anon-expanded TPU. In addition, the sole 1110 optionally comprises a foil1101 by means of which the outsole 1113 is connected to a first surfaceregion 1111. In this context, the foil serves as carrier material and/orcompound material and/or stabilizing element. Further, the sole 1110optionally comprises a frame element 1114.

FIG. 17 shows other embodiments of a shoe 1700 with a sole comprising atleast a first partial region 1705 covered by a foil 1710 by means ofwhich a torsion bar or reinforcement element 1720 as well as outsoleelements 1730, 1732, 1734 and 1736 are attached to the midsole. The foilmay only cover the bottom surface or parts of the bottom surface of themidsole, as described in more detail with reference to FIGS. 19 a-bbelow, or it may further extend around the outer rim of the sole orparts thereof, as also described in more detail with reference to FIGS.18 a-b below, for example to provide further stability to the sole ormidsole. The outsole elements 1730, 1732, 1734 and 1736 may alsopartially cover the torsion bar or reinforcement element 1720. Thishelps to avoid slipping of the foot that could occur otherwise in casethe sole makes contact with the ground on the hard reinforcement element1720. In other embodiments, the torsion bar or reinforcement element1720 could also be disposed between the partial region 1705 and the foil1710 in order to secure the element 1720 in its place and to protect itagainst mechanical and/or chemical influences. If disposed in such a wayunder the foil, the risk of slipping might be reduced, even withoutfurther outsole elements if the foil itself provides enough friction.The foil could, for example, be made of high friction TPU. Anotheroption would be to structure the midsole on its bottom surface so thefoil adapts that shape to increase the friction of the sole. Acombination of both options is also possible. This could help to saveweight in the construction of a light-weight sole, e.g. for a sports orrunning shoe.

FIGS. 18 a-b show embodiments of a shoe 1800 comprising a midsolecomprising a first surface region 1810 arranged in the forefoot regionand a third surface region 1820 arranged in the heel region, bothcomprising expanded TPU, as well as a second surface region 1830comprising expanded PP. Dotted line 1890 indicates the approximateextension of the first surface region 1810 and dotted line 1892indicates the approximate extension of the third surface region 1820. Asalready discussed, in certain embodiments, the ratio of expanded PP andexpanded TPU may be about 70% expanded PP to about 30% expanded TPU. Inother embodiments, the expanded TPU comprises about 10%-40% of theentire sole, depending on the specific sole design and intended use ofthe sole. As can furthermore be seen, the first surface region 1810placed in the midfoot and/or forefoot region may be shaped to provide acushioning underneath the big toe. This results in more energy beingapplied to the push off movement of the foot, e.g. during running, andprovides more energy to the overall movement of the foot. Thisassistance of the push off movement over the big toe also helps toimprove the running/walking efficiency. It is to be appreciated,however, that the lines 1890 and 1892 merely serve illustrative purposesin order to give a person skilled in the art an idea of an exemplaryextension of the first and third surface elements, respectively.

They may not be construed as detailed constructional specifications.Also shown is a textile reinforcement element 1840 provided to increasethe stability of the sole while saving most of the weight of e.g. atorsion bar. The textile reinforcement element may be made of a numberof materials as already discussed above. The textile reinforcementmaterial may be attached to at least a part of the first, second and/orthird surface region. In general, such a textile reinforcement elementmay be attached to at least a part of one or more surface and/or partialregions of a sole in a number of different ways beneficial to thestability of the sole. As a further option, the textile reinforcementmaterial may also be sandwiched between two or more layers of the soleor midsole comprising TPU and this multi-layer laminate may then be usedin a sole for a shoe. The first, third and second surface regions 1810,1820 and 1830, as well as the textile reinforcement material 1840 arecovered by a foil 1850. In the embodiments shown in FIGS. 18 a-b, thefoil covers the bottom as well as the sides or outer rim of the midsole.In this configuration, the foil protects the bottom of the midsole andalso helps to stabilize the shape of the second surface regioncomprising expanded PP. The edge of the foil is indicated by the dashedline 1895. Again, this line only serves illustrative purposes and maynot be construed as a detailed constructional specification. In someembodiments, the foil comprises TPU. The foil 1850 also helps to securethe textile reinforcement element 1840 in its place and to furtherprotect the first, third and second surface regions 1810, 1820 and 1830and the textile reinforcement material 1840 against mechanical and/orchemical influences as already mentioned above. Outsole elements 1860are disposed on the foil in order to help avoid slipping of the shoe. Inother embodiments not shown, further inner or outer sole elements like atorsion bar or another textile reinforcement material may additionallybe disposed beneath the foil or on the outside of the foil to furthermodify the functionality and characteristics of the sole. The foil mayalso be colored, such as with a color comprising liquid TPU such that aparticularly durable coloring may be achieved. In an additional aspect,one or more of the surface regions comprising TPU may be colored, suchas using a color comprising liquid TPU.

FIGS. 19 a-b show other embodiments of a shoe 1900 comprising a midsolecomprising a first surface region 1910 arranged in the forefoot regionand a third surface region 1920 arranged in the heel region, bothcomprising expanded TPU, as well as a second surface region 1930comprising EVA, such as light weight EVA so that the entire sole has aweight of less than about 100 g. Although such a light weight EVAmaterial might not be suitable for the construction of a completemidsole because of its performance parameters, it may be usedadvantageously together with one or more inserts and/or surface regionsand/or partial regions comprising expanded TPU. Dotted line 1990indicates the approximate extension of the first surface region 1910 anddotted line 1992 indicates the approximate extension of the thirdsurface region 1920. As already discussed, in certain embodiments, theexpanded TPU comprises about 10%-40% of the entire sole, depending onthe specific sole design and intended use of the sole. As canfurthermore be seen, the first surface region 1910 placed in the midfootand/or the forefoot region may be shaped to provide a cushioningunderneath the big toe. This results in more energy being applied to thepush off movement of the foot, e.g. during running, and provide moreenergy to the overall movement of the foot. This assistance of the pushoff movement over the big toe also helps to improve the running/walkingefficiency. It is to be appreciated, however, that the lines 1990 and1992 merely serve illustrative purposes in order to give a personskilled in the art an idea of an exemplary extension of the first andthird surface elements, respectively. They may not be construed asdetailed constructional specifications. Also shown is a textilereinforcement element 1940 provided to increase the stability of thesole while saving most of the weight of e.g. a torsion bar. The textilereinforcement element may comprise a number of materials as alreadydiscussed above. The first, third and second surface regions 1910, 1920and 1930, as well as the textile reinforcement element 1940 are coveredby a foil 1950. In the embodiments shown in FIGS. 19 a-b, the foil onlycovers the bottom but not the sides of the midsole, since the foil isnot needed to stabilize the shape of the second surface regioncomprising EVA in this case. The edge of the foil is indicated by thedashed line 1995. Again, this line only serves illustrative purposes andmay not be construed as a detailed constructional specification. In someembodiments, the foil comprises TPU. The foil 1950 helps to secure thetextile reinforcement element 1940 in its place and to further protectthe first, third and second surface regions 1910, 1920 and 1930 and thetextile reinforcement element 1940 against mechanical and/or chemicalinfluences. Outsole elements 1960 are disposed on the foil in order tohelp avoid slipping of the shoe. In other embodiments not shown, furtherinner or outer sole elements like a torsion bar or another textilereinforcement material may additionally be disposed beneath the foil oron the outside of the foil to further modify the functionality andcharacteristics of the sole. In a further optional aspect the foil orone or more surface regions of the midsole may be colored, such as usinga color comprising liquid TPU.

FIGS. 12 a-c show embodiments for an insole 1200 for a shoe, wherein theinsole comprises expanded TPU. The insole comprises a first partialregion 1201 with a first expanded TPU and an optional second partialregion 1202 with a second expanded TPU. The first expanded TPU 1201 isarranged in the region of the balls of the toes. The second partialregion 1202 is arranged in the region underneath the calcaneus. Thus, aninsole is provided that is particularly cushioning in the mentionedregion. Hence, a particularly pleasant wearing comfort is achieved. Thefirst and the second expanded TPU in the partial regions 1201 and 1202may be glued to the remaining part of the insole or connected to theremaining part of the insole by other means. In other embodiments, thefirst and/or second partial regions are bonded to the remaining parts ofthe insole in a steaming process for the first and/or second expandedTPU.

In other embodiments, the first partial region 1201 and/or the secondpartial region 1202 may be arranged differently than in FIGS. 12 a-c.The first and second expanded TPU may be manufactured from differentbase material and/or with a different steaming process. A variety ofdesign possibilities for an improved insole is obtained. Since an insolemay be easily replaced for example by an insole of a different type, thecushioning properties of a sole may be substantially changed by simplyexchanging the insole 1200. Thus, one and the same shoe may be adaptedto different types of sports by means of differently adapted insoles.For example, a running shoe that is actually adapted for sprinting andtherefore comprises a sole with a rather high strength may also be usedfor long-distance running with an insole that comprises expanded TPU.Particularly, due to its long-term stability, expanded TPU is very wellsuited to provide insoles with large cushioning.

The insole 1200 may be coated at its upper face with known means inorder to provide a surface that is pleasant for contacting the foot. Theinsole 1200 may, in some embodiments, at least partially be surroundedby a foil, in particular a plastic foil. The latter may improve thefunctionality of the insole. In particular, it may reduce the effect ofdirt and water on the insole and thus further increase the lifetime ofthe insole 1200. Moreover, the foil may modify further functionalproperties of the expanded TPU of the insole 1200 such as for examplethe cushioning, in a similar manner as already discussed above.Alternatively or additionally, the foil may provide the insole 1200 witha desired texture, haptics and/or color.

FIGS. 13 a-c show other embodiments of an insole 1300 for a shoe,wherein the insole comprises expanded TPU. The insole 1300 may bemanufactured in a steaming process for the expanded TPU. The expandedTPU of the insole 1300 may be designed differently according to thespecific needs. Thus, by means of changing the insole, differentfunctionalities may be achieved. For example, the cushioning of the solemay be varied by means of different insoles. In this context, on the onehand, the large cushioning and the long-term stability that may beachieved by means of expanded TPU are advantageous. On the other hand,by means of expanded TPU, an insole may be provided with differentproperties even if it has the same dimensions, particularly the samethickness. Thus, for example the cushioning of the sole may be modifiedwithout the foot having to adapt to a changed geometry of the shoe.

Moreover, for example also the weight of the insole or the cushioning ofthe insole may be adapted to the weight of the wearer accordingly. Insome embodiments, the insole 1300 comprises a first and a second partialregion with a first a second expanded TPU. Also more than two partialregions with two or more expanded TPU may be included.

In addition, by means of an insole, which comprises expanded TPU, thesole of a shoe may be designed thinner and thus more cost-effective andlighter since already by means of the insole a strong cushioning isprovided such that the requirements to the sole of the shoe are lower.By means of a thin sole and the proximity to the ground which isassociated therewith, a particularly natural wearing comfort may beachieved.

In certain embodiments, a shoe with an insole that comprises expandedTPU is provided. By means of the large cushioning that is provided bythe insole, an additional intermediate sole of the shoe is unnecessary.Thus, the wearer of the shoe has the possibility to exchange thefunctionality that is usually provided by an intermediate sole—and whichcannot be exchanged—by means of exchanging the insole.

In addition, in some embodiments for a shoe, the outsole may be arrangedin such a minimalistic manner that it only comprises a layer that isdirectly attached to the bottom of the shoe upper. The layer maycomprise rubber or TPU and only partially covers the lower face of theupper. Thus, a particularly flat shoe with a natural walking and runningfeeling due to proximity to the ground may be provided. The layer may bemelted onto the upper.

The insole 1300 may be precisely shaped by means of a steaming processfor the expanded TPU. Thus, the insole 1300 may be provided with avarying thickness. In addition, the shape of the insole 1300 may bedesigned in an anatomically optimized manner.

In particular in the context of insoles, a lower temperature-dependenceof the material properties is desirable. Typically, an insole heats upin the course of usage to the body temperature of the foot. At thebeginning of the usage, however, it is colder—for normal outsidetemperatures. Thus, the temperature of the insole usually stronglychanges while wearing it. By means of the lower temperature-dependenceof the properties of expanded TPU, an insole may be provided that onlyminimally changes its properties in the course of time. A shoe with aninsole that comprises expanded TPU thus immediately provides the desiredproperties.

FIG. 13 d show different embodiments of an insole 1301 for a shoe,wherein the insole 1301 comprises expanded TPU. The insole 1301 ismanufactured from a block that comprises expanded TPU. For example, theinsole 1301 may be cut or die-cut. The insole 1301 comprises aparticularly simple and cost-effective way for providing an insole witha large cushioning and long-term stability as well as lowtemperature-dependence. In certain embodiments, the insole 1301comprises a plastic foil and/or a different cover, such as for examplesweat absorbing textile or a textile reinforcement material.

In further embodiments, one of the described insoles or one of thedescribed partial regions of a sole/insole or one of the describedsurface regions of a sole/insole may comprise an expanded TPU that ismanufactured from expanded TPU particles with different properties. Forexample, a first type of TPU particles with a first particle size and asecond type of TPU particles with a second particle size may be used tomanufacture an expanded TPU. Alternatively or additionally, the firsttype of TPU particles may differ from the second type of TPU particlesby one or more other properties, for example color. In addition, theinsole may be colored, such as using a color comprising liquid TPU.

Additional elements, such as a foil and/or a textile reinforcementmaterial and/or color comprising liquid TPU, may furthermore be used incombination with an insole in essentially the same way as alreadydescribed in previous embodiments to the beneficial effects alreadydiscussed.

FIG. 14 a shows a method 1400 for manufacturing a shoe sole, inparticular a shoe sole for a sports shoe. It comprises loading 1410 amold with an expanded TPU. In addition, it optionally comprises relaxing1420 of the TPU. The method further comprises feeding of steam 1430 tothe expanded TPU. The feeding of steam heats the expanded TPU. Thesurface of the expanded TPU melts such that the expanded TPU is bondedto a closed plastic foam structure.

The loading 1410 with expanded TPU may comprise the loading withexpanded TPU in the form of expanded particles. These may be provided inthe form of loose material. The size of the particles is designed suchthat they comprise diameters of about 0.5 mm to about 25 mm. Thediameters of the particles may further comprise about 2 mm to about 10mm, and may even further comprise about 3 mm to about 8 mm.

An advantage of the use of expanded particles is that these particlesmay be bonded together in a random arrangement. They do not have to bealigned or oriented in a particular way during manufacturing to providethe advantageous effects discussed herein.

In some embodiments, the loading 1410 comprises the steps 1411 and 1412.The particles are loaded into the mold with atmospheric pressure in step1411. Subsequently, they are pressurized within the mold in step 1412.To this end, a variety of different methods may be used. For example, itmay be achieved by reducing the volume of the mold. In some embodiments,to this end, a moveable part of the mold is moved such that the volumeof the mold is reduced. In further embodiments, the mold is designedsuch that the pressure within the mold is locally varied.

In other embodiments, the loading 1410 comprises the step 1413. Theparticles are loaded into the mold already under pressure—if desiredwith a locally varying pressure. That way, the manufacturing method maybe accelerated.

The pressure to which the particles are compressed in method 1400essentially influences the density and the strength of the expanded TPU.The diameter of the particles reduces by means of applying the pressure.For higher pressures, the particles are compressed and densified morestrongly. By reducing the pressure 1420, the particles of the expandedTPU essentially re-expand to their original diameters.

By means of the feeding of steam 1430 to the expanded TPU, the latter isheated. The surface of the particles is partially melted or melted.Thus, the particles may chemically bond to each other. They bond to agranular but closed plastic foam structure.

In some embodiments, the method in addition comprises the loading of themold with a material that is free from expanded TPU, for a secondsurface region, wherein the expanded TPU is provided for a first surfaceregion. Thus, the expanded TPU may be bonded to a variety of othermaterials without additional gluing means in a steaming process. Forexample, the material that is free from expanded TPU is loaded into themold first, wherein the expanded TPU is loaded into the moldsubsequently. In other embodiments, this sequence may however also bechanged. In addition, also several loading steps with expanded TPU orwith different expanded TPU and/or several loading steps with materialthat is free from expanded TPU may be carried out. Therein, the sequenceof the steps may be optimized differently in different embodiments.

In other embodiments, the method comprises the loading of the mold witha second expanded TPU for a second partial region, wherein the alreadymentioned first TPU is provided for a first partial region. In addition,the feeding of steam further comprises feeding the steam to the secondexpanded TPU. The first and the second expanded TPU are compresseddifferently or comprise different pressures and/or different basematerials. Thus, several partial regions that comprise differentproperties may be precisely manufactured in one fabrication method. Forexample, the partial regions may be bonded to each other by means of thefeeding of steam. Steam may be fed to both partial regionssimultaneously. In other embodiments, the first partial region may befed with steam first and the second partial region may be fed with steamsubsequently. The subsequent feeding of steam and the merging ofindividual partial regions may be carried out in a suitable mold. Forexample, after the melting of a first partial region in a designatedregion, the mold is opened only to an extent such that a loading and afurther melting of expanded TPU particles is enabled, which may forexample form a further partial region.

In some embodiments, already expanded partial regions of expanded TPUmay be loaded into a mold. By means of feeding steam, also then partialregions may be bonded to each other.

The described methods may be automatized to a large degree that allows acost-effective and efficient production. Moreover, the problematic usageof glue is unnecessary and may harm the environment and the workers inthe shoe production. Only steam is added in the production process. Insome embodiments, the steam is essentially free from additives.

FIG. 14 b shows further embodiments for a method 1450 for manufacturinga shoe sole that comprises a loading of a mold with expanded TPU underincreased pressure. In step 1451, the mold is closed and pre-treatedwith steam. Thus, for example the mold may be cleaned. In step 1452, themold is loaded with expanded TPU particles, wherein the loading iscarried out under pressure. In step 1453 the pressure relaxes within themold. In step 1454 steam is fed to the expanded TPU such that thesurfaces of the particles partially melt and the particles chemicallybond to each other. In addition, the method comprises, in step 1455, acooling of the mold with water and/or air that are fed through the mold.Thus, the expanded TPU is cooled indirectly via the mold. Thus, thebonding process is stopped and the expanded TPU acquires the closedplastic foam structure. Finally, the mold is re-opened in step 1456 andthe sole, which comprises expanded TPU, is removed from the mold.

FIG. 14 c shows further embodiments for a method 1460 for manufacturinga shoe sole that comprises a loading of a mold with expanded TPU underatmospheric pressure.

In step 1461, the mold, which comprises a movable part, is opened to apredetermined extent. The mold is loaded with expanded TPU particles atatmospheric pressure in step 1462. In step 1463, the volume of the moldis reduced according to the predetermined shape of the element that isto be manufactured and which comprises expanded TPU. Thus the expandedTPU is compressed. The extent to which the mold is opened and, thus, theamount of particles that are available for the compression of theparticles is essential for the mechanical properties of the element.That way, the weight, the strength and the elasticity of the expandedTPU may be determined. The extent to which the mold is opened is alsocorrespondingly adapted to the size of the shaped part. In someembodiments, the mold is opened to a height of about 14 mm for loading.Thus, a medium weight and a medium strength of the expanded TPU areachieved. If the weight of the expanded TPU—for the same geometry—is tobe reduced and/or it is to be designed softer, the mold is opened, insome embodiments, in the range of for example about 10 mm to about 14mm. For a larger weight and a harder element, the mold may, in someembodiments, be opened up to about 20 mm. In other embodiments, theheight of the opening of a mold depends on the shoe size for which theexpanded TPU, which is to be manufactured, is provided. For larger shoesizes, by trend, larger forces are to be expected, such that theexpanded TPU correspondingly may be arranged with higher strength.Correspondingly, the mold is opened to a larger extent for larger shoesizes.

In step 1464, steam is fed to the expanded TPU. The expanded TPU ispartially melted. In these embodiments, steam is fed to the expanded TPUalready during the process of closing the mold. In other embodiments,the steps 1463 and 1464 may also be carried out subsequently. In step1465, the mold is cooled by means of water and/or air and thus theexpanded TPU is cooled indirectly. In step 1466 the mold is finallyopened and the sole is removed from the mold.

In other embodiments the steps of the mentioned methods formanufacturing a sole for a shoe may be combined. Also, individual methodsteps may be left out or may be carried out in a different order.

FIGS. 15 a-e show embodiments for molds that may be used for one of thementioned methods for manufacturing a sole for a shoe, in particular asports shoe.

FIG. 15 a shows an example for a mold 1510 in an opened and a closedstate. The mold 1510 comprises a fixed element 1511 and a movableelement 1512. In some embodiments, the mold is opened to a predeterminedextent and loaded with expanded TPU. Subsequently, the moveable element1512 is moved towards the fixed element 1511 such that the expanded TPUis compressed. The mold is closed to a predetermined extent, whichdetermines the thickness of the shaped element that comprises expandedTPU. In these embodiments, steam is fed to the expanded TPU during theprocess of closing. The two elements 1511 and 1512 are arranged suchthat their shape determines the geometry of the shaped element thatcomprises expanded TPU.

FIG. 15 b shows a further example for a mold 1520. In addition to thefixed element 1511, the mold 1520 comprises a first moveable element1522 and a second moveable element 1523. The number of two moveableelements in FIGS. 15 b-c is only an example and other molds may comprisemore than two moveable elements. The different moveable elements 1522and 1523 allow opening the mold to different extents in differentregions. Thus, for example in the region below the element 1522, whichis opened to a larger extent than element 1523, a higher density may beprovided after closing the mold than in the region below the element1523. Thus, for example a surface region or a partial region of a solemay be provided with a higher mass and a higher strength in the heelregion than a partial region or a surface region in the toe region.

FIG. 15 c shows a mold 1530 which, in addition to the fixed element1511, also comprises two moveable elements 1532 and 1533. Moreover, themold 1530 comprises a separating element 1534 that separates the regionsbelow the elements 1532 and 1533. Thus, the regions below the elements1532 and 1533 may be advantageously loaded with different basematerials, for example a first expanded TPU 1535 and a second expandedTPU 1536. The first and the second expanded TPU may for example comprisea different particle size and/or color and/or composition. Theseparating element 1534 prevents the first and second TPU 1535 and 1536,respectively, from mixing during the loading. In some embodiments, theseparating element 1534 is removed prior to compressing in order toconnect the regions below the elements 1532 and 1533. In otherembodiments, the separating element is removed after compressing. Inboth embodiments, the first and second TPU 1535 and 1536, respectively,may be merged such that a bonding between the first and the second TPUis provided. In some embodiments, the moveable elements 1532 and 1533may also be opened to different extents prior to loading.

FIG. 15 d shows a further example 1540 of a mold that comprises a fixedelement 1511 and a moveable element 1542. In addition to an expanded TPU1546, the mold may also be loaded with a material 1547, which is freefrom expanded TPU. This may for example be a functional element forexample a torsion bar.

Also, the molds 1510, 1520 and 1530 may be loaded with such elements. Inthese embodiments, the material that is free from TPU is loaded into themold prior to the expanded TPU. In some embodiments, several materialsor elements that are free from expanded TPU may be loaded into the mold.After the merging, the mold may also be opened and loaded once again.Thus, a further or several further steaming processes may be carried outsubsequently in order to provide further partial regions that compriseexpanded TPU or which are free from expanded TPU on top of each other.

FIG. 15 e shows a three-dimensional view of a mold 1550. The lattercomprises a fixed element 1551 and a moveable element 1552. Moreover,FIG. 15 e shows the sole 1110 that is manufactured within the mold 1550.As described above with respect to FIG. 11 b, the sole 1110 comprisesthe first surface region 1111 that comprises an expanded TPU, theoutsole 1113 and the frame element 1114, as well as the optional foil1101. In some embodiments of a method, first, the outsole 1113, theoptional foil 1101, and subsequently the frame element 1114 are loadedinto the mold. Then, the mold is then loaded with an expanded TPU. Themold is closed and steam is fed to the expanded TPU such that theexpanded TPU is partially melted in order to bond with the frame element1114, the outsole 1113 and/or optionally the foil 1101.

The features of the molds 1510, 1520, 1530, 1540, 1550 and the methodsteps associated therewith may, in some embodiments, also be combined inan arbitrary manner.

FIG. 16 shows another example of a process 1600 for steam molding forexample a sole for a shoe, comprising the steps of (1) loading materialto a hopper vessel 1610, (2) closing the mold 1620, (3) filling the moldcavities via pressure and/or through a crack via crack fill with thematerial to be molded, for example expanded PP or expanded TPU, 1630,(4) steaming the material within the mold 1640, (5) cooling andstabilizing the steamed material 1650, and (6) demolding 1660.

It is to be appreciated that the material loaded into the mold may alsocomprise more than one base material, e.g. expanded PP and expanded TPU,or expanded TPU comprising different particle sizes and/or color or thelike, and that these different components may be fused together by thesteam energy under pressure to welt together and form one uniquecomponent by the methods and processes described above.

Each of the mentioned methods for manufacturing a sole for a shoe mayalso comprise a curing of an expanded TPU. Thus, the properties of theexpanded TPU may be improved. In particular, the curing may stabilizethe structure of the expanded TPU.

For example, the properties of an expanded TPU may be influenced byparameters of the added steam. First, the temperature of the added steaminfluences the strength of the melting of the particle surfaces. Highersteam temperatures create stronger bonding of the particles.Additionally, the strength of the bonding may be controlled via theduration of the steaming process.

In certain embodiments, the duration of the method comprises about 3-15minutes. The duration may further comprise about 3-6 minutes for lesselaborate methods, wherein only a few different materials and/orelements are used. For methods that involve a plurality of materialsand/or elements, the duration may comprise up to about 15 minutes.

A higher initial pressure, which is used for compressing the expandedTPU particles, by trend, leads to a larger density of the expanded TPU.The densities of the expanded TPU may vary from about 30 to about 300grams/liter, and may further vary from about 70 to about 250grams/liter.

By means of a slower cooling of the expanded TPU, its structure may bestabilized. Thus, a higher long-term stability is achieved. Also, bymeans of curing the expanded TPU, its structure may be stabilized,wherein the curing temperature and curing duration influence thestabilization of the structure.

The properties of an expanded TPU may also be influenced by the choiceof the base material. For example, expanded TPU particles of differentsizes may be used. By trend, the larger the particles, the more porousthe foam structure of the expanded TPU will be. Moreover, withincreasing particle size, the expanded TPU will, by trend, be lessdense, lighter, and softer. In addition, a plethora of additives may beadded to the base material of the expanded TPU, which may control theproperties of the expanded TPU. For example, a different expandedmaterial may be added to the expanded TPU as a base material. To makethe material lighter, for example, expanded PP or expanded PS may beadded. To make the material stronger, for example, expanded PA may beadded. For specific applications, materials of very different kinds maybe combined. Thus, the properties of the expanded TPU may be preciselychanged in order to provide particular predetermined properties.

In total, a large flexibility for controlling the properties of theexpanded TPU is provided. Flexibility may be achieved by both changingthe base material and by changing the manufacturing parameters as wellas by adjusting the base materials and the manufacturing parameters toeach other. In particular, the manufacturing parameters, such as theextent of opening the mold, the temperature and pressure, may be changedvery easily and quickly such that the manufacturing process may beprovided in a very flexible and quickly changeable manner.

In the following, further examples are described to facilitate theunderstanding of the invention:

-   -   1. Sole (210; 310; 410; 510; 710; 810) for a shoe (200; 300;        400; 700; 800), in particular a sports shoe, comprising        -   a. at least a first (211; 311; 411; 511; 711; 811) and a            second (212; 312; 412; 512; 712; 815) surface region,        -   b. wherein the first surface region (211; 311; 411; 511;            711; 811) comprises an expanded thermoplastic polyurethane            (TPU) and        -   c. wherein the second surface region (212; 312; 412; 512;            712; 815) is free from expanded TPU.    -   2. Sole (210; 310; 410; 510; 710; 810) according to example 1,        wherein the surface regions (211; 212; 311; 312; 411; 412; 511;        512; 711; 712; 811; 815) are bonded to each other by a steaming        process for the TPU.    -   3. Sole (210; 310; 410; 510; 710; 810) according to any of        examples 1 or 2, wherein the second surface region (212; 312;        412; 512; 712; 815) comprises a foamed ethylene-vinyl acetate        and/or non-expanded TPU and/or rubber and/or polypropylene        and/or polyamide and/or polystyrene.    -   4. Sole according to example 3, wherein the second surface        region comprises expanded polypropylene.    -   5. Sole (210; 310; 410; 510; 710; 810) according to one of the        preceding examples, wherein the second surface region (212; 312;        412; 512; 712; 815) is arranged at a rim of the sole (210; 310;        410; 510; 710; 810).    -   6. Sole (210; 310; 410; 510; 710; 810) according to one of the        preceding examples, wherein the second surface region (212; 312;        412: 512; 712; 815) comprises a sole plate (516) and/or a        torsion bar and/or an outsole (213; 313; 413; 713; 813) and/or a        recess (214) for receiving functional elements.    -   7. Sole (310; 510; 710; 810) according to one of the preceding        examples, wherein the first surface region (311; 511; 711; 811)        comprises a varying thickness.    -   8. Sole (310; 510; 710) according to example 7, wherein the        thickness of the first surface region (311; 511; 711) increases        from the forefoot region towards the heel region.    -   9. Sole (510) according to one of the preceding examples,        wherein the first surface region (511) comprises at least one        recess.    -   10. Sole (310; 510; 710; 810) according to one of the preceding        examples, wherein the first surface region (311; 511; 711; 811)        is arranged at a rim of the sole (310; 510; 710; 810).    -   11. Sole (710) according to example 10, wherein the thickness of        the first surface region (711) is increased at the rim of the        sole.    -   12. Sole (310; 410; 510; 710; 810) according to one of the        preceding examples, wherein the first surface region (311; 411;        511; 711; 811) is arranged in the midfoot region and/or in the        forefoot region of the sole (310; 410; 510; 710; 810).    -   13. Sole (210; 410) according to one of the preceding examples,        wherein the sole comprises a third surface region (2111; 4112)        that comprises an expanded TPU.    -   14. Sole (210) according to example 13, wherein the first        surface region (211) is arranged in the heel region of the sole        (210) and wherein the third surface region (2111) is arranged in        the midfoot region and/or in the forefoot region of the sole        (210).    -   15. Sole according to example 12, wherein the sole further        comprises a partial region that is arranged in the heel region        of the sole.    -   16. Sole according to example 15, wherein the partial region        comprises a heel insert comprising an elastomer compound.    -   17. Sole according to one of the preceding examples, wherein the        first surface region and/or the third surface region and/or the        partial region are surrounded by the second surface region.    -   18. Sole according to one of the preceding examples further        comprising a textile reinforcement material.    -   19. Sole according to example 18, wherein the textile        reinforcement material is attached to at least a part of the one        or more surface regions and/or a part of the partial region.    -   20. Sole according to one of the preceding examples, wherein the        one or more surface regions and/or the partial region are at        least partially surrounded by a foil, in particular a plastic        foil.    -   21. Sole according to example 20, wherein the foil comprises        TPU.    -   22. Sole according to one of the examples 20 or 21, wherein the        foil is bonded to at least a part of the one or more surface        regions and/or a part of the partial region by partially melting        at least one of the foil or a part of the one or more surface        regions and/or a part of the partial region.    -   23. Sole according to one of the examples 20-22, wherein the        foil is bonded to at least a part of the one or more surface        regions and/or a part of the partial region by a chemical        reaction.    -   24. Sole according to one of the examples 20-23, wherein the        foil is imprinted on the side of the foil that is facing the one        or more surface regions and/or the partial region.    -   25. Sole according to one of the examples 20-24, wherein the        foil serves to attach at least one inner sole element to at        least one of the surface regions and/or the partial region.    -   26. Sole according to one of the examples 20-25, wherein at        least one outer sole element is affixed to the side of the foil        that is facing away from the one or more surface regions and/or        the partial region.    -   27. Sole according to examples 25 or 26, wherein the at least        one inner sole element and/or the at least one outer sole        element comprise a sole plate and/or an outsole element and/or a        torsion bar and/or a textile reinforcement material.    -   28. Sole according to one of the preceding examples, wherein at        least one of the surface regions comprising TPU and/or the foil        comprising TPU is colored with a color comprising liquid TPU.    -   29. Sole (810; 910; 1010; 210; 410) for a shoe (800; 900; 1000;        200; 400), in particular a sports shoe, comprising        -   a. a first partial region (811; 911; 10111; 211; 411), which            comprises a first expanded thermoplastic polyurethane (TPU),        -   b. a second partial region (812; 912; 10112; 2111; 4112),            which comprises a second expanded TPU,        -   c. wherein the first expanded TPU and the second expanded            TPU are manufactured using a different steaming process            and/or using a different base material.    -   30. Sole (810; 910; 1010; 210; 410) according to example 29,        wherein the first expanded TPU comprises a first particle size        and wherein the second expanded TPU comprises a second particle        size that differs from the first particle size.    -   31. Sole (810; 910; 1010) according to any of the examples 29 or        30, wherein the partial regions (811; 812; 911; 912; 10111;        10112) are bonded to each other by a steaming process for the        first expanded TPU and/or the second expanded TPU.    -   32. Sole (910) according to any of the examples 29-31, wherein        the first partial region (911) comprises a first sole layer and        the second partial region (912) comprises a second sole layer.    -   33. Sole (910) according to example 32, wherein the sole        comprises a third sole layer (913) that is free from expanded        TPU.    -   34. Sole according to example 33, wherein the third sole layer        is arranged between the first and second sole layer.    -   35. Sole (210; 410) according to any of the examples 29-31,        wherein the first partial region (211; 411) comprises a first        surface region and/or the second partial region (2111; 4112)        comprises a second surface region.    -   36. Sole according to example 35, wherein the first surface        region is arranged essentially on the medial side of the sole.    -   37. Sole according to example 36, wherein the second surface        region is arranged essentially on the lateral side of the sole.    -   38. Sole according to one of the examples 29-37 further        comprising a textile reinforcement material.    -   39. Sole according to example 38, wherein the textile        reinforcement material is attached to at least a part of the one        or more partial regions.    -   40. Sole according to one of the examples 29-39, wherein one or        more partial regions are at least partially surrounded by a        foil, in particular a plastic foil.    -   41. Sole according to example 40, wherein the foil comprises        TPU.    -   42. Sole according to one of the examples 40 or 41, wherein the        foil is bonded to at least a part of the one or more partial        regions by partially melting at least one of the foil or a part        of the one or more partial regions.    -   43. Sole according to one of the examples 40-42, wherein the        foil is bonded to at least a part of the one or more partial        regions by a chemical reaction.    -   44. Sole according to one of the examples 40-43, wherein the        foil is imprinted on the side of the foil that is facing the one        or more partial regions.    -   45. Sole according to one of the examples 40-44, wherein the        foil serves to attach at least one inner sole element to at        least one of the partial regions.    -   46. Sole according to one of the examples 40-45, wherein at        least one outer sole element is affixed to the side of the foil        that is facing away from the one or more partial regions.    -   47. Sole according to examples 45 or 46, wherein the at least        one inner sole element and/or the at least one outer sole        element comprise a sole plate and/or an outsole element and/or a        torsion bar and/or a textile reinforcement material.    -   48. Sole according to one of the examples 29-47, wherein at        least one of the partial regions comprising TPU and/or the foil        comprising TPU is colored with a color comprising liquid TPU.    -   49. Sole according to one of the preceding examples, wherein the        sole has a weight of less than about 100 g.    -   50. Insole (1200; 1300) for arrangement within the upper of a        shoe, in particular a sports shoe, wherein the insole (1200;        1300) comprises an expanded thermoplastic polyurethane (TPU).    -   51. Insole according to example 50 further comprising a textile        reinforcement material.    -   52. Insole (1200; 1300) according to examples 50 or 51, wherein        the insole (1200; 1300) is at least partially surrounded by a        foil, in particular a plastic foil.    -   53. Insole according to example 52, wherein the foil comprises        TPU.    -   54. Insole according to one of the examples 52 or 53, wherein        the foil is bonded to the insole by partially melting at least        one of the foil or the insole.    -   55. Insole according to one of the examples 52-54, wherein the        foil is bonded to the insole by a chemical reaction.    -   56. Insole according to one of the examples 52-55, wherein the        foil is imprinted on the side of the foil that is facing the        insole.    -   57. Insole according to examples 50-56, wherein at least one of        the insole and/or the foil comprising TPU is colored with a        color comprising liquid TPU.    -   58. Shoe (200; 300; 400; 700; 800; 900; 1000), in particular        sports shoe, comprising a sole (210; 310; 410; 510; 710; 810;        910; 1010; 1110) according to one of the preceding examples.    -   59. Shoe (200; 300; 400; 700; 800; 900; 1000) according to        example 58 comprising an upper (220; 320; 420; 720; 820; 920;        1020), wherein the sole (210; 310; 410; 510; 710; 810; 910;        1010; 1110) is bonded to the upper in a steaming process without        gluing means.    -   60. Method (1400; 1450; 1460) for manufacturing a shoe sole, in        particular a shoe sole for a sports shoe, comprising:        -   loading (1411; 1413; 1452; 1462) a mold with an expanded            thermoplastic polyurethane (TPU), for a first surface            region;        -   loading the mold with a material that is free from expanded            TPU, for a second surface region;        -   feeding steam (1430; 1454; 1464) to the expanded TPU.    -   61. Method (1400; 1450; 1460) for manufacturing a shoe sole, in        particular a shoe sole for a sports shoe, comprising:        -   loading (1411; 1413; 1452; 1462) a mold with a first            expanded thermoplastic polyurethane (TPU), for a first            partial region;        -   loading the mold with a second expanded TPU, for a second            partial region;        -   feeding steam (1430; 1454; 1464) to the first and second            expanded TPU;        -   wherein the first and second expanded TPU comprise a            different density and/or a different base material.    -   62. Method according to any of the examples 60 or 61, wherein        the expanded TPU or the first and/or the second expanded TPU        comprises particles.    -   63. Method according to example 62, further comprising:        -   partially melting the surface of the particles.    -   64. Method according to any of the examples 60-63, further        comprising:        -   compressing (1412; 1463) the expanded TPU or the first            and/or the second expanded TPU.    -   65. Method according to any of the examples 60-63, wherein the        loading (1413; 1452) of the expanded TPU or the first and/or the        second expanded TPU is carried out under pressure.    -   66. Method according to any of the examples 60-65, further        comprising:        -   relaxing (1420) the expanded TPU or the first and second            expanded TPU.    -   67. Method according to any of the examples 60-66, further        comprising:        -   cooling (1455; 1465) the expanded TPU or the first and            second expanded TPU.    -   68. Method according to any of the examples 60-67, further        comprising:        -   curing the expanded TPU or the first and second expanded            TPU.

Different arrangements of the components depicted in the drawings ordescribed above, as well as components and steps not shown or describedare possible. Similarly, some features and sub-combinations are usefuland may be employed without reference to other features andsub-combinations. Embodiments of the invention have been described forillustrative and not restrictive purposes, and alternative embodimentswill become apparent to readers of this patent. Accordingly, the presentinvention is not limited to the embodiments described above or depictedin the drawings, and various embodiments and modifications may be madewithout departing from the scope of the claims below.

1.-20. (canceled)
 21. A sole comprising at least a first surface regionand a second surface region; wherein the first surface region comprisesan expanded thermoplastic polyurethane; wherein the second surfaceregion is free from expanded thermoplastic polyurethane; and wherein atleast a portion of the second surface region is arranged along an outerrim of the sole and is arranged in an area between a forefoot region anda heel region of the sole.
 22. The sole according to claim 21, whereinthe second surface region is shaped to surround the first surfaceregion.
 23. The sole according to claim 22, wherein the second surfaceregion is shaped to restrict extension of the first surface region. 24.The sole according to claim 21, further comprising a recess for anelectronics unit.
 25. The sole according to claim 21, wherein the secondsurface region comprises at least one of foamed ethylene-vinyl acetate,non-expanded thermoplastic polyurethane, rubber, polypropylene,polyamide, polystyrene, and expanded polypropylene.
 26. The soleaccording to claim 21, wherein the sole has a weight of less than about100 g.
 27. The sole according to claim 21, wherein the first surfaceregion comprises less than about 40% of the sole.
 28. A shoe comprisingthe sole of claim
 21. 29. The sole according to claim 21, furthercomprising a third surface region comprising an expanded thermoplasticpolyurethane.
 30. The sole according to claim 29, wherein the expandedthermoplastic polyurethane of the first surface region comprises ahigher strength than the expanded thermoplastic polyurethane of thethird surface region.
 31. The sole according to claim 29, wherein thefirst surface region is arranged in the heel region of the sole and thethird surface region is arranged in the forefoot region of the sole. 32.The sole according to claim 31, wherein the expanded thermoplasticpolyurethane of the first surface region comprises a higher strengththan the expanded thermoplastic polyurethane of the third surfaceregion.
 33. A sole comprising at least a first surface region and asecond surface region, wherein the first surface region comprises anexpanded thermoplastic polyurethane; wherein the second surface regionis free from expanded thermoplastic polyurethane; wherein at least aportion of the second surface region is shaped to surround the firstsurface region; and wherein the first surface region is arranged in atleast one of a forefoot region and a heel region.
 34. The sole accordingto claim 33, wherein the first surface region comprises less than about40% of the sole.
 35. The sole according to claim 33, further comprisinga recess for an electronics unit.
 36. The sole according to claim 33,wherein the second surface region comprises at least one of foamedethylene-vinyl acetate, non-expanded thermoplastic polyurethane, rubber,polypropylene, polyamide, polystyrene, and expanded polypropylene.
 37. Asole comprising at least a first surface region, a second surfaceregion, and a third surface region; wherein the first surface region andthe third surface region comprise an expanded thermoplasticpolyurethane; wherein the second surface region is free from expandedthermoplastic polyurethane; and wherein the second surface region isshaped to restrict extension of the first surface region and the thirdsurface region
 38. The sole according to claim 37, wherein at least aportion of the second surface region is shaped to separate and surroundthe first surface region and the third surface region.
 39. The soleaccording to claim 37, further comprising a recess for an electronicsunit.
 40. The sole according to claim 37, wherein the expandedthermoplastic polyurethane of the first surface region comprises ahigher strength than the expanded thermoplastic polyurethane of thethird surface region.
 41. The sole according to claim 37, wherein thesecond surface region comprises at least one of foamed ethylene-vinylacetate, non-expanded thermoplastic polyurethane, rubber, polypropylene,polyamide, polystyrene, and expanded polypropylene.
 42. The soleaccording to claim 37, wherein the sole has a weight of less than about100 g.
 43. The sole according to claim 37, wherein the first surfaceregion and the third surface region comprise less than about 40% of thesole.
 44. A shoe comprising the sole of claim 37.